The Ultimate Guide to Generator Load Calculation

Choosing a backup generator is a big decision, and it’s easy to feel overwhelmed by the technical details. The biggest fear? Spending thousands on a unit that can’t power your essentials when you need them most. This is precisely why a generator load calculation is your most important first step. It’s a simple analysis that removes all the guesswork. As the key to proper load calculation for generator sizing, it gives you one precise number—the exact amount of power your home requires. Armed with this information, you can choose the right Generac generator with total confidence.

Key Takeaways

A Load Calculation is Your Power Blueprint: Before choosing a generator, you must calculate your home’s specific power needs. This critical first step prevents the common pitfalls of an undersized unit that fails under pressure or an oversized one that wastes fuel.
Account for the Startup Surge: An accurate calculation includes two key parts: the total running watts for all your devices, plus the single highest starting watts from a motor-driven appliance like an AC unit or well pump. Forgetting this initial power jolt is a frequent and costly mistake.
Plan for Today and Tomorrow: After calculating your total wattage, add a 25% safety margin to cover any future additions and ensure your generator isn’t overworked. For complete accuracy, a professional consultation is the best way to guarantee your investment is a perfect fit for years to come.

What is a Generator Load Calculation? (And Why You Can’t Skip It)

Think of a generator load calculation as creating a power budget for your home or business. Before you can choose the right backup power solution, you need a clear picture of exactly what you need to run during an outage. This calculation is the critical first step in that process. It’s a detailed assessment of all the appliances, lights, and systems you want to power, from your refrigerator and HVAC unit to your computers and well pump.

This isn’t just about adding up a few numbers. A proper load calculation accounts for how much power each device needs to start up and how much it needs to run continuously. Getting this right is the foundation of a reliable backup power system. It ensures the Generac generator you choose is perfectly matched to your needs—not too small to handle the load and not too large to be inefficient. Skipping this step or relying on a rough guess can lead to frustrating performance issues and unexpected costs down the road. It’s the single most important thing you can do to guarantee your generator will be there for you when you need it most.

Understanding Generator Sizing

At its core, generator sizing is about matching your power needs with the right equipment. The process starts with making a comprehensive list of every item you consider essential during a power outage. For each item, we identify its power consumption in watts. A key part of this is understanding that some appliances, especially those with motors like air conditioners or refrigerators, require a much larger surge of power to start than they do to run. We account for both of these figures to ensure the generator can handle those initial power demands without faltering. Finally, we add a safety margin of about 20-25% to provide a buffer, ensuring your generator can handle unexpected loads and isn’t constantly running at its absolute limit.

What Happens When You Get It Wrong?

Choosing the wrong size generator can cause significant problems. If your generator is too small for your needs, it will constantly be overloaded. This can cause it to shut down frequently, or worse, lead to permanent damage to both the generator and the appliances connected to it. It’s like asking a small car to pull a heavy trailer—it’s simply not built for that kind of strain. On the other hand, a generator that’s too large is also a problem. It will run inefficiently, wasting fuel and leading to higher operating costs over its lifetime. An oversized unit can also experience its own set of maintenance issues from not running at its optimal load. That’s why a professional residential standby generator installation always begins with a precise calculation to find that perfect fit.

How to Find the Wattage of Your Appliances

Before you can choose the right generator, you need to figure out exactly how much power you’ll need. This starts with a simple but important task: calculating the total wattage of the appliances and equipment you plan to power during an outage. It’s not just about adding up numbers; you also have to understand that different devices have different power demands, especially when they first turn on. Let’s walk through how to find this information and what it all means for your home or business.

Where to Look for Wattage Information

The first step is to make a list of every item you want your generator to run. For each item, you’ll need to find its wattage. Most appliances have a data plate or sticker on the back or bottom that lists electrical specifications. Look for the number followed by a “W” for watts. If you can’t find the wattage directly, look for the amps (A) and volts (V). You can calculate the wattage yourself with a simple formula: Volts x Amps = Watts. For example, an appliance that uses 120V and 5A needs 600 watts. This appliance energy calculator from the Department of Energy can also help you estimate usage for common household items.

Running Watts vs. Starting Watts: What’s the Difference?

You’ll notice that some appliances, and all Generac generators, list two types of wattage: running and starting.

Running watts (or rated watts) is the continuous power an appliance needs to operate normally after it has started.
Starting watts (or surge watts) is the extra burst of power an appliance needs for a few seconds just to turn on.

Think of it like pushing a car; it takes a big initial shove to get it moving (starting watts), but much less effort to keep it rolling (running watts). Both numbers are critical for sizing your generator correctly, as the generator must be able to handle both the initial surge and the continuous load.

Why Some Appliances Need More Power to Start

Appliances with electric motors are the main reason we have to pay attention to starting watts. Things like your refrigerator, air conditioner, well pump, or sump pump require a significant jolt of electricity to get their motors spinning. This initial power draw can be two to five times higher than their normal running wattage. If your generator can’t supply this surge, the appliance won’t start, and you could overload the generator. This is why accurately accounting for the highest starting wattage among your essential items is a key step in planning your residential standby generator installation.

How to Calculate Your Generator Load, Step-by-Step

Alright, you’ve done your homework and have a good handle on what running and starting watts are. Now comes the fun part: putting it all together to figure out exactly what size generator you need. This calculation is the most important step in ensuring your lights stay on and your essential systems keep running smoothly during an outage. Getting this right means you’ll have reliable power without overspending on a unit that’s too large or, worse, getting a generator that can’t handle the load. Let’s walk through the process step-by-step.

Step 1: List All Your Essential Appliances

First things first, grab a notepad or open a new document and walk through your home or business. Make a complete list of every single appliance, light, and device you want to power during an outage. Think beyond the obvious like the refrigerator and freezer. Do you need your sump pump to prevent flooding? What about your well pump for water? Consider medical equipment, your home office computer and router, security systems, and even a few lights and outlets for charging phones. The more detailed your list, the more accurate your final calculation will be, setting you up for a successful residential standby generator installation.

Step 2: Add Up the Total Running Watts

Once you have your comprehensive list, find the running (or continuous) wattage for each item. You should find this on the appliance’s label or in its owner’s manual. Now, simply add all of those numbers together. This sum gives you the total amount of power your generator will need to produce continuously to keep everything on your list running at the same time. This figure is your baseline power requirement—the minimum steady power your generator must supply. Think of it as the total energy your home consumes on a normal basis when all those items are active.

Step 3: Find the Highest Starting Wattage

This is a step that’s easy to miss but absolutely critical for appliances with motors. Things like your air conditioner, refrigerator, or well pump require a significant surge of extra power just to get started. Look at your list and identify the item with the single highest starting wattage. You only need to find the one with the biggest number, as it’s highly unlikely all your major appliances will start up at the exact same second. Take that single highest starting wattage and add it to your total running wattage from Step 2. This ensures your Generac generator can handle that initial jolt of power without tripping a breaker.

Step 4: Add a Safety Buffer

Finally, it’s always a good idea to give yourself a little wiggle room. Once you have your total from Step 3, multiply it by 1.25 (or add 25%) to create a safety margin. This buffer does a few important things. It accounts for any future appliances you might add, ensures your generator isn’t constantly running at its absolute maximum capacity (which is better for its longevity), and covers any small inaccuracies in the listed wattage of your current devices. This foresight helps protect your investment and ensures your system requires only routine generator maintenance to stay in top shape for years to come.

A Step-by-Step Calculation Example

Let’s put this into practice with a real-world example. Imagine you want to power a few key items during an outage. After making your list, you find the following wattages:

Refrigerator: 800 Running Watts / 2,200 Starting Watts
Sump Pump: 1,050 Running Watts / 2,150 Starting Watts
A few lights: 100 Running Watts
TV and Internet Router: 220 Running Watts

First, add up the running watts: 800 + 1,050 + 100 + 220 = 2,170 total running watts. Next, find the single highest starting wattage, which is the refrigerator at 2,200 watts. Add this to your running total: 2,170 + 2,200 = 4,370 watts. Finally, add the 25% safety buffer: 4,370 x 1.25 = 5,463 watts. This final number tells you that you need a Generac generator capable of producing at least 5,500 watts to confidently power your essentials. While this calculation is a fantastic starting point, a professional consultation is the best way to guarantee a perfect fit for your residential standby generator installation.

Alternative Load Calculation Methods

While the step-by-step manual calculation is a great starting point, other methods can provide an even more precise picture of your power needs. These approaches are especially useful for complex residential setups or for commercial properties where power demands are higher. Think of these as the next level of accuracy, ensuring your generator investment is perfectly tailored to your real-world usage. They move from theoretical lists to data-driven analysis, giving you the most accurate information possible before making a final decision.

Using Past Utility Bills

One practical way to understand your power consumption is to look at your own history. Your past utility bills contain a wealth of information, specifically your peak electricity demand over the last year. By analyzing this data, you can see the maximum power your home or business has drawn from the grid. This gives you a real-world baseline for your needs. To ensure you’re covered, take that peak demand figure and add a safety margin of about 25%. This approach helps you confidently select a Generac generator that can handle your proven maximum load.

Measuring with a Clamp-On Ammeter

For ultimate precision, nothing beats a direct measurement. A clamp-on ammeter is a specialized tool an electrician uses to measure the exact electrical current an appliance draws in real-time. This method is incredibly useful for determining the precise running and starting watts of your major appliances, especially those with large motors like HVAC units or well pumps. It removes all guesswork, replacing estimates with hard data. Getting these exact figures is a key part of a professional assessment and ensures your generator is sized with pinpoint accuracy, especially for complex commercial loads.

Guidelines for Commercial Buildings

Sizing a generator for a business is a different ballgame. It’s unlikely that every piece of equipment in a commercial facility will run at the same time. This is where professionals use a “diversity factor,” a guideline that accounts for staggered usage by sizing the generator for 70-85% of the total connected load. Applying this factor prevents the common mistake of oversizing the unit, which leads to fuel inefficiency and maintenance issues. A proper commercial generator installation always involves these detailed calculations to ensure the system is both powerful and efficient.

Tips for an Accurate Generator Load Calculation

Getting your generator size right is a bit like packing for a trip—you want to be prepared for everything without carrying more than you need. A precise load calculation is the key to finding that perfect balance. Unfortunately, a few common missteps can lead to choosing a generator that’s either too small to handle the load or unnecessarily large and costly. Let’s walk through the most frequent mistakes so you can sidestep them and feel confident in your choice. Making an informed decision now saves you from headaches, frustration, and unexpected costs when the power goes out.

Forgetting About Startup Wattage

One of the easiest mistakes to make is looking only at the running wattage of your appliances. Many devices, especially those with motors like your refrigerator, air conditioner, or well pump, need a significant surge of extra power just to get started. This is called starting wattage or surge wattage. If your generator can’t provide this initial jolt, the appliance won’t turn on, or worse, it could trip the generator’s circuit breaker. When we perform a residential standby generator installation, we always account for these power-hungry startups to ensure everything runs smoothly from the moment the generator kicks on.

Overlooking Technical Details

It’s tempting to just add up the wattage of everything you own and call it a day, but a proper load calculation is more nuanced. You probably won’t be running your microwave, all the lights, the TV, and the sump pump at the exact same time. Professionals use what’s called a diversity factor to create a realistic estimate of your actual power usage at any given moment. Sizing a generator for 100% of your connected load is often overkill. A professional assessment finds the sweet spot, ensuring your Generac generator has enough power for your needs without being overworked or oversized.

Not Planning for Future Power Needs

Your power needs today might not be your power needs five years from now. Are you planning to finish your basement and add a home theater? Thinking about installing a central air conditioning system or an electric vehicle charger? These additions can significantly increase your electricity demand. When you invest in a generator, it’s wise to think ahead. Choosing a model that only meets your bare-minimum current needs could mean you’ll have to upgrade sooner than you’d like. Factoring in future growth ensures your generator will serve you well for years to come.

Skipping Permits and Paperwork

Guessing your wattage needs is a recipe for trouble. A proper load analysis isn’t a back-of-the-napkin calculation; it’s a detailed process that involves carefully listing each appliance and circuit you want to power. This structured approach ensures nothing gets missed, from the smallest light fixture to the largest HVAC unit. For businesses, this is even more critical, as a commercial generator installation must support essential operations without fail. Taking the time to do the math correctly—or having a professional do it for you—is the single most important step in choosing the right generator.

Tools and Tips for an Accurate Calculation

Getting your generator load calculation right is part science, part art. While the steps we’ve covered will give you a solid estimate, a few professional tools and insights can help you fine-tune the numbers for complete accuracy. Think of your initial calculation as a detailed sketch; these tips are how you add the color and shading to get the full picture.

Accuracy is key because it ensures your generator will perform flawlessly when you need it most. It prevents the stress of an undersized unit failing during an outage or the unnecessary cost of an oversized one. Using the right tools and understanding a few technical details will give you confidence in your final decision.

Using an Online Load Calculator

While a pen and paper are great for a preliminary list, professionals use specialized software to ensure nothing gets missed. These tools can model different scenarios and account for complex factors more accurately than a simple spreadsheet. Some manufacturers even offer their own sizing calculators to help match load requirements to specific models. Ultimately, the most valuable tool is an experienced technician who knows how to interpret that data and apply it to your specific home or business needs for a Generac generator. They bring practical knowledge that software alone can’t provide.

Why Keeping Good Records Matters

When it comes to sizing a generator, real-world data always beats theory. The most accurate way to understand your power needs is to look at your actual usage. For homeowners, this can be as simple as reviewing your monthly utility bills to find your peak consumption. For businesses, this might involve a more formal energy audit. This documentation provides a clear, evidence-based picture of your consumption patterns. Having this data on hand helps a professional recommend a generator that’s truly tailored to your operational needs, especially for a commercial generator installation.

kW vs. kVA: What’s the Difference?

As you research generators, you’ll likely see two power ratings: kilowatts (kW) and kilovolt-amperes (kVA). In simple terms, kW is the “actual power” an appliance uses, while kVA is the “apparent power,” or total power consumed. The difference is called the power factor. For example, a facility with a 400 kW load and a 0.80 power factor actually needs a 500 kVA generator. While the difference is small for most homes, it’s a critical detail that a professional will handle during a residential standby generator installation to ensure your unit is sized correctly.

Understanding Power Factor

Think of power factor as a measure of electrical efficiency. It’s the ratio of the actual power your appliances use (real power, measured in kW) to the total power the generator is producing (apparent power, measured in kVA). In a perfect world, these two numbers would be the same, giving you a power factor of 1.0. However, appliances with motors, like air conditioners and pumps, create “reactive power” that doesn’t do any real work but still puts a load on the generator. A low power factor means your generator is working harder and burning more fuel to deliver the power you actually need, which can lead to strain and potential damage over time. This is why our team carefully considers these factors to ensure your Generac generator is a perfect match for your home’s unique electrical profile.

Why You Should Regularly Test Your Load

A load calculation tells you what your generator should do, but a load test proves that it can. A load test is essentially a stress test for your generator, confirming it can produce the required power without overheating or failing. This isn’t just a one-time check; it’s a critical part of a good maintenance plan. It verifies that the engine, alternator, and cooling system are all working together as they should under pressure. Think of it as a fire drill for your power system—it’s the best way to ensure everything works when it counts and a key part of any Generac maintenance plan.

Single-Phase vs. Three-Phase Power

When discussing power, you’ll often hear the terms “single-phase” and “three-phase.” Think of it like the difference between a one-lane road and a three-lane highway. Single-phase power, common in most homes, delivers electricity along a single wave. It’s perfectly sufficient for running everyday appliances like your lights, TV, and refrigerator. Three-phase power, on the other hand, delivers three waves of electricity in a continuous, smooth flow. This makes it ideal for larger operations that need to run heavy-duty equipment. While most residential setups require single-phase power, nearly all businesses will need a three-phase system to support their machinery, making it a key consideration for any commercial generator installation.

Key Formulas for Accurate Calculations

While you don’t need to be a math whiz to understand your power needs, it’s helpful to know that professionals use precise formulas to get the job done right. These calculations convert a generator’s power rating—measured in kilowatts (kW) or kilovolt-amperes (kVA)—into the actual electrical current (amps) it can supply. To do this, an electrician considers the generator’s voltage, its power rating, and a variable called the “power factor.” This level of detail ensures that the generator selected is a perfect match for your home’s electrical system. It’s one of the many technical details that a certified technician handles to ensure your Generac generator operates safely and effectively from day one.

Calculating Full Load Current (Amps)

Every generator has a maximum “full load current,” which is the highest amount of amperage it can safely produce when running at full tilt. Think of it as the absolute maximum weight a bridge is designed to hold. Knowing this number is essential because it dictates the size of the circuit breakers and wiring needed for a safe installation. Exceeding this limit can cause the generator to shut down or, in a worst-case scenario, damage the unit and your connected appliances. A professional calculates this figure precisely to ensure your entire backup power system is balanced, protected, and ready to handle the demand during an outage.

The 80% Rule for Generator Safety

Just because a generator *can* run at 100% capacity doesn’t mean it *should* for long periods. A key industry best practice is the “80% rule,” which advises that you should only plan to continuously use about 80% of your generator’s full load current. It’s similar to not redlining your car’s engine constantly. This approach provides a crucial safety buffer, prevents overheating, and reduces wear and tear on the engine and electrical components. Following this rule not only extends the life of your generator but also ensures it runs more efficiently, minimizing the need for unexpected generator service and repair and giving you peace of mind.

Considering Altitude and Site Conditions

A generator’s performance isn’t determined in a vacuum. Environmental factors at your specific location can play a surprising role in its actual power output. For example, generators lose a small percentage of their power for every thousand feet of elevation above sea level because the air is thinner. Extreme heat can also impact performance. While our service areas in Southeastern Pennsylvania don’t have extreme altitudes, these are the kinds of details a professional technician assesses during a site visit. They will consider all the unique conditions of your property to ensure the generator they recommend will deliver the power you expect, no matter the weather.

How to Choose the Right Generac Generator

Once you have your total wattage calculated, you’re ready for the exciting part: matching your power needs to the perfect generator. Think of your load calculation as a blueprint. It gives you the exact specifications you need to find a reliable power solution that won’t let you down when you need it most. This final step is all about translating your numbers into the right piece of equipment for your home or business, ensuring you get a generator that’s just right—not too big and not too small.

Matching Your Load to a Generac Model

Your load calculation is your guide to the wide world of Generac generators. To find the right fit, you’ll start by calculating the total wattage needs of the appliances and systems you plan to power. Remember that most generators have both running watts and starting watts, which are crucial for determining the appropriate model. With your final number in hand, you can confidently browse models knowing exactly what capacity you’re looking for. Whether you need to power just the essentials, like your refrigerator and sump pump, or want the peace of mind that comes with a whole-home unit, your calculation will point you in the right direction.

What Different Generator Sizes Can Power: An Example

To make this more concrete, let’s look at a couple of scenarios. Say your load calculation shows you need about 10,000 watts to cover your absolute essentials: the refrigerator, freezer, sump pump, a few lights, and your home office setup. A smaller Generac model, perhaps in the 10kW to 14kW range, would be a perfect fit, ensuring your critical systems stay online. However, if you want to maintain a higher level of comfort and run your central air conditioning, electric water heater, and other high-demand appliances, your calculation might be closer to 20,000 watts. In that case, you’d be looking at a whole-home unit, like a 22kW or 24kW model, to provide seamless, comprehensive power without compromise.

Beyond the Watts: Fuel Type, Noise, and Other Features

While your wattage calculation is the most important factor, it isn’t the only one. You’ll also want to consider the fuel source. Most standby generators run on natural gas or liquid propane, and the right choice depends on what’s available and convenient for your property. Noise level is another key consideration, especially in residential areas with neighbors close by. Generac’s Guardian Series is known for being quiet, but it’s still something to be aware of. Finally, think about features like remote monitoring, which lets you check your generator’s status from your phone. A professional residential standby generator installation will cover all these options to ensure your final choice is a perfect match for your home and lifestyle.

When in Doubt, Size Up

It can be tempting to choose a generator that just meets your calculated wattage to save a little money upfront, but it’s always smarter to give yourself a buffer. We recommend adding a safety margin of about 25% to your total. This isn’t about buying more than you need; it’s about protecting your investment. This extra capacity ensures your generator isn’t constantly running at its maximum output, which reduces wear and tear and promotes a longer lifespan. It also gives you the flexibility to add new appliances in the future without worrying if your generator can handle the extra load. This foresight helps ensure your system will only need routine generator maintenance to serve you reliably for years.

Why a Professional Consultation Is a Smart Move

While a DIY calculation is an excellent starting point, it’s best not to rely on theory alone when making such an important investment. For truly accurate sizing, a professional can perform a demand study of your actual load over time to capture peak usage. An expert consultation for your residential standby generator installation ensures nothing gets missed. We can identify “phantom loads,” account for the specific power demands of modern electronics, and discuss your future needs, like a planned home addition or a new hot tub. This professional check guarantees your generator will be a perfect fit for years to come.

When Should You Call a Professional?

For businesses and facilities with complex power needs, an expert consultation is non-negotiable. Most commercial buildings with substantial motor loads, like HVAC systems or manufacturing equipment, can benefit from a professional assessment. An expert can evaluate factors like power factor correction to optimize your generator size, which can impact both upfront and long-term costs. A hospital, for example, might install a 1500 kW generator for critical loads rather than a 3000 kW unit for the entire facility. For any commercial generator installation, getting an expert involved from the start ensures your operations stay online safely and efficiently during an outage.

Common Reasons for Generator Failure (Besides Sizing)

You’ve done the hard part. You’ve walked through your home, tallied up your appliances, and calculated your exact power needs. Choosing a generator with the right capacity is a huge step, but it’s not the final one. Even a perfectly sized generator can fail to perform when you need it most if it isn’t installed and cared for correctly. Think of it like a high-performance car—it has all the power you need, but it won’t get you anywhere without a skilled mechanic to set it up and a solid maintenance schedule to keep it running.

The long-term reliability of your generator depends on two critical factors that happen after the purchase: the quality of the installation and the consistency of its upkeep. These elements are just as important as the initial load calculation. A flawless installation ensures your generator integrates seamlessly with your home’s electrical system, while routine maintenance keeps it in a constant state of readiness. Overlooking these areas can lead to frustrating and preventable failures, undermining the very peace of mind you sought to achieve with your investment.

Poor Installation or Wiring

A standby generator is a sophisticated piece of equipment that ties directly into your home’s electrical heart—the circuit breaker panel. This is not a simple plug-and-play device. A poor installation can create a host of problems, with faulty wiring being a primary culprit. Issues like loose connections, damaged wires, or an improperly installed transfer switch can prevent the generator from starting, cause it to shut down intermittently, or even create a serious safety hazard. These problems are often hidden from view, only revealing themselves during an actual power outage when it’s too late. That’s why a professional residential standby generator installation by certified electricians is so important; it guarantees every connection is secure and every component works exactly as it should from day one.

Maintenance Issues: Batteries and Airflow

More often than not, a generator fails to start for a surprisingly simple reason: a weak or dead battery. Just like a car battery, a generator’s starting battery can lose its charge over time, especially if it sits unused. It’s the single most common point of failure, yet it’s also one of the easiest to prevent. Beyond the battery, other basic engine needs can be overlooked. Old, stale fuel can clog the system, low oil levels can cause the engine to seize, and dirty air filters can restrict airflow, causing the unit to overheat and shut down. These are the fundamentals of engine health, and regular Generac maintenance ensures these simple but critical checks are never missed, so your generator is always ready to answer the call.

Frequently Asked Questions

Can’t I just buy a bigger generator to be safe and skip the detailed calculation? While it might seem like a safe bet, getting a generator that’s too large for your needs can cause its own set of problems. An oversized unit runs inefficiently, which wastes fuel and can lead to premature wear and maintenance issues over time. The goal is to find the perfect fit, ensuring the generator runs at its optimal load to give you reliable, efficient power for years.

What’s the single biggest mistake people make with their load calculation? The most common oversight is forgetting about starting watts. People often add up the regular running wattage of their appliances and call it a day, but they forget that items with motors—like your air conditioner or well pump—need a huge burst of power to get started. If your generator can’t handle that initial surge, it will trip or fail, leaving you in the dark right when you need it most.

Does this calculation work for both my home and my business? Yes, the fundamental process of listing your essential equipment and adding up the wattage is the same for both. However, commercial calculations are often more complex. They need to account for things like three-phase power, specialized machinery, and the critical nature of business operations. While a homeowner can get a great estimate on their own, a business should always start with a professional assessment.

What happens if my power needs change after my generator is installed? This is a great question and exactly why we recommend planning for the future. If you add a major appliance like an EV charger or finish your basement, your power needs will increase. A generator that was perfectly sized before might now be too small. This is why building in a safety margin during the initial calculation is so important, as it provides a buffer for minor additions. For significant changes, it’s best to consult a professional to see if your current system can handle the new load.

I’ve done the math, but I’m still not sure. What’s the next step? Doing the calculation yourself is an excellent way to understand your power needs and budget. But for an investment this important, getting a second opinion from a professional is always a smart move. An expert can verify your numbers, spot things you might have missed, and discuss your specific goals to ensure the Generac model you choose is a perfect match for your property.

Generator Load Calculation: A Step-by-Step Guide