What Size Generator for House in California?

Figuring out the right size generator for your house isn't about square footage—it's about what you absolutely need to keep running. For just the essentials, like your refrigerator and a few lights, a 5,000-7,500 watt generator will usually do the trick. If you want to add some key comforts, like a home office or a small AC unit, you’ll need to step up to 10,000-15,000 watts. And if you want to run your entire home without missing a beat, you’re looking at 20,000 watts or more.

Why Your Generator Size Is So Important

Picking a home generator is about so much more than just buying a piece of equipment; it's about securing your peace of mind. For homeowners here in California, that decision has become more critical than ever. Between the constant threat of Public Safety Power Shutoffs (PSPS) and an aging grid, reliable backup power has shifted from a luxury to a flat-out necessity.

This isn't just a local trend. The global demand for residential generators is expected to skyrocket to $15.1 billion by 2030, all because of grid instability. Most homeowners start with generators up to 6,000 watts (6 kW), which is plenty to cover basic household needs like lights and the fridge during an outage. You can learn more about the growth of the residential generator market here.

Three Core Scenarios for Sizing

To nail down what size generator your house needs, start by picturing an outage and asking yourself which of these scenarios fits you best:

• Bare Essentials: You just need the absolute fundamentals online. Think refrigerator, freezer, a couple of lights, and a spot to charge your phone. Nothing fancy.

• Key Comforts: You want the essentials, but you also need to keep your modern life running. This means powering your home office, internet router, and maybe the television.

• Whole-Home Power: You don't want to even know the power is out. This is the "business as usual" approach, where everything from your central air conditioning to the electric stove keeps running seamlessly.

Picking the wrong size is a costly mistake. An undersized generator can get overloaded, potentially damaging your appliances and the generator itself. Go too big, and you're just wasting fuel and money. The real goal is to perfectly match the generator's output to what your family actually needs.

Getting this right from the start means you’ll have dependable power without breaking the bank. Ready to find that perfect fit for your home? Contact RC Generators and Electric for a professional assessment tailored to the unique needs of your California home.

Quick Guide to Home Generator Sizing

To give you a starting point, we've put together this quick reference table. It breaks down common power needs and the generator size you'll likely want to consider.

Remember, this is just an estimate. A professional load calculation is the only way to know for sure what your home requires.

Demystifying Generator Watts for Homeowners

Before you can figure out what size generator your house needs, you have to speak the language of power: watts. Every generator has two wattage numbers listed, and understanding the difference is key to protecting both your home and your investment.

Think of it like trying to push a heavy, stalled car. The massive effort it takes just to get the wheels turning is the starting wattage. Once it’s rolling, the steady, lighter push needed to keep it moving is the running wattage.

Why Starting Watts Are So Important

Appliances with motors—like your refrigerator, well pump, or air conditioner—work exactly the same way. They need a huge surge of power for a few seconds to kick their motors into gear. This initial jolt is the starting wattage, often called "surge" wattage.

After that initial burst, the appliance settles into a much lower, more consistent power draw. That's its running wattage. This distinction is one of the most important factors in choosing the right generator.

An undersized generator that can't supply the needed starting watts will either stall or shut down. This not only leaves you in the dark but can seriously damage your appliance's motor and the generator itself from the strain.

The Dangers of Getting It Wrong

Picking a generator based only on the running watts of your appliances is a common mistake. For example, a refrigerator might only use 700 running watts, but it could demand 2,100 starting watts just to get its compressor going. If your generator’s maximum output is only 2,000 watts, it just doesn’t have the muscle for that startup surge.

This is why understanding both numbers is so critical. You have to account for the single highest starting wattage among all your essential appliances, plus the running wattage of everything else you plan to power at the same time. To see how a generator produces this power in the first place, you can learn more about how a home generator works.

To size your generator the right way, you’ll need to:

1. Identify the Biggest Surge: Find the highest starting wattage requirement among all the appliances you need to power.

2. Add Up the Running Load: Sum the running watts for all devices you plan to operate simultaneously.

3. Calculate Your Total Need: Your generator must have a running wattage capacity that exceeds your total from step two and a starting wattage capacity that can handle the biggest surge from step one.

Once you’ve got a handle on these concepts, you can confidently move forward and figure out exactly what your home’s power needs are.

How to Calculate Your Home's Actual Power Needs

Alright, now that you understand the difference between starting and running watts, it’s time to figure out your needs. We're moving from theory to the real world—your world. Forget the guesswork and generic advice. We're going to figure out the exact number you need to confidently answer the question, “what size generator do I need for my house?”

This is way easier than it sounds, and honestly, it’s pretty empowering. We'll walk through how to list your essential appliances, find out how much juice they need, and add it all up. By the end, you'll have a solid, reliable figure that makes shopping for the right generator a breeze.

Step 1: List Your Must-Have Appliances

First things first, grab a notepad or open a new note on your phone. Picture this: the power goes out in your California home. What devices are absolutely non-negotiable for your family’s comfort and safety?

Your list should be a reflection of your priorities. For many homeowners, this means thinking about what you'd need to get through a multi-day outage, whether it’s from a wildfire threat or a summer heatwave.

Common essentials usually include:

• Refrigerator and Freezer: You’ve got to prevent hundreds of dollars of food from spoiling.

• Lights: A few in key spots like the kitchen, a main hallway, and a bathroom.

• Phone and Laptop Chargers: Staying connected and informed is critical.

• Well Pump: If you're in a rural area, this is your water supply. It's a must.

• Sump Pump: For homes in areas prone to flooding, this is non-negotiable.

• Medical Equipment: Any device that's vital for someone's health and well-being.

Once you have the basics down, think about a few comforts. Maybe it's the internet router so you can keep your home office running, or a television to keep up with news updates. The goal is to paint a realistic picture of what you'll actually need during an outage.

Step 2: Find the Wattage for Each Item

With your list ready, the next step is to find the running watts and starting watts for each appliance. Remember, running watts are what the appliance needs to operate continuously, while starting watts are that extra jolt of power required to get it going.

You can usually find this info on a sticker or small metal plate on the appliance itself, often tucked away near the power cord. If it’s not there, a quick online search for the model number or a peek at the owner’s manual should do the trick.

To give you a head start, this infographic shows the typical wattage demands for common kitchen appliances.

As you can see, something like a refrigerator needs a serious initial kick to get its compressor running. That's the starting wattage in action.

For a more comprehensive look, here’s a quick reference chart for other common household items.

Common Household Appliance Wattage Chart

This table gives you a ballpark idea of the power draw for various appliances. Keep in mind that these are estimates—your specific models might be a little different, so always check the label if you can.

Using a chart like this helps you quickly estimate your needs if you can't find the exact numbers on your appliances.

Step 3: Calculate Your Total Power Requirement

Okay, let's do the math. It’s much simpler than it looks and only involves two quick calculations:

1. Total Running Watts: Just add up the running watts of all the appliances you plan to power at the same time. This number is the baseline power your generator has to provide continuously.

2. Total Starting Watts: Now, look at your list and find the single appliance with the highest starting wattage. Take that one number and add it to your total running watts from the first step.

That second number—your total starting watts—is your magic number. It tells you the minimum surge capacity your generator must have to handle the biggest power draw without getting overloaded.

This simple calculation is the most accurate way to figure out what size generator your house really needs. For most homes, the final number lands somewhere between 5,000 and 10,000 watts (5 kW to 10 kW), which is usually enough to cover all the essentials. If you're curious about broader market trends, you can discover more insights about residential generator capacities here.

With your exact wattage calculated, you’re ready to find the perfect generator. For a professional load calculation and expert installation in Los Angeles or Ventura County, contact RC Generators and Electric today for a free consultation.

Choosing the Right Type of Generator for Your Needs

You've done the hard work and calculated your wattage needs. Now comes the fun part: matching that number to the right generator. Your home’s power requirements will point you toward one of three main options, and picking the right one is key to a solution that fits both your lifestyle and your budget.

Think of it like choosing a vehicle. You wouldn't buy a sleek sports car to haul lumber, and you wouldn't take a semi-truck on a quick trip to the grocery store. The generator you choose should be perfectly suited for the job you've laid out for it.

The Three Main Types of Home Generators

Let's get to know the main players in home backup power. Each one serves a different purpose, from keeping a few essentials running to powering your entire home without a single hiccup.

• Portable Generators: These are the versatile workhorses of the generator world. They usually run on gasoline and are an affordable option upfront. You can move them wherever you need power, making them perfect for handling a few key items like a refrigerator and some lights.

• Inverter Generators: Think of these as a quieter, more sophisticated version of a portable generator. Inverters produce "clean" power, which is essential for sensitive electronics like computers and smart TVs. They're also more fuel-efficient and operate with less noise, making them an excellent choice for keeping a home office online or for use in neighborhoods with noise restrictions.

• Standby Generators: This is the top-tier solution for home backup power. A standby generator is permanently installed outside your home and hooked up directly to your electrical panel. The moment the power cuts out, it kicks on automatically. Since they typically run on natural gas or propane, they can provide long-term, whole-home power without you having to lift a finger.

A standby generator is all about true peace of mind. It’s a set-it-and-forget-it system that ensures everything in your home—from the central AC to your security system—keeps running without interruption. That’s a massive advantage during California's extended outages.

Making the Best Choice for Your Home

The demand for reliable home power has grown like never before. In 2023, the global market for residential standby generators was valued at around $1.8 billion, a number driven by an increase in severe weather events and an aging grid infrastructure. This trend makes one thing clear: homeowners are moving toward permanent, automated solutions. Find out more about the rising demand for standby generators.

Standby units are especially popular because they completely eliminate the hassle of refueling and manual setup in the middle of an emergency. To get a better sense of the specific advantages they offer, you can read our guide on the benefits of a Generac standby generator.

At the end of the day, the best generator is the one that meets your calculated wattage needs, fits within your budget, and gives you the level of convenience you're looking for. If you have significant power needs or simply want a seamless, automatic solution, a standby generator is almost certainly the best investment for your home.

Ready to find the perfect generator for your California home? Contact RC Generators and Electric today for a professional consultation and expert installation.

Real Sizing Scenarios for California Homeowners

Theory is one thing, but seeing how generator sizing plays out in the real world is what really makes it all click. Let’s walk through a few common situations California homeowners find themselves in. These stories help turn abstract wattage calculations into tangible peace of mind.

Seeing how different families figure out their priorities will help you visualize your own. You'll feel much more confident when it's time to decide what size generator your house needs.

Scenario 1: The Rural PSPS Event

First up, meet a family living in a rural slice of Ventura County, where Public Safety Power Shutoffs (PSPS) are just a part of life during fire season. Their number one concern? The electric well pump. No pump, no water. It's that simple.

Their list of "must-haves" is short but critical:

• Well Pump (1 HP): 2,000 running watts | 4,000 starting watts

• Refrigerator: 800 running watts | 2,200 starting watts

• A few LED lights: 100 running watts | 100 starting watts

• Phone Chargers: 50 running watts | 50 starting watts

First, they add up their running watts: 2,000 + 800 + 100 + 50 comes out to 2,950 running watts.

Next, they find the single biggest power surge on their list—that well pump at a hefty 4,000 watts. Adding that to the running total gives them a peak requirement of 6,950 watts. A 7,500-watt portable generator is the perfect solution here, giving them a comfortable buffer without breaking the bank.

Scenario 2: The Suburban Summer Heatwave

Now let’s head over to a family in a Los Angeles suburb. When a summer heatwave puts a major strain on the grid, they want to keep their home office online and, more importantly, stay cool. For them, it's all about comfort and productivity.

Here's their power breakdown:

• Window AC Unit: 1,200 running watts | 1,800 starting watts

• Refrigerator: 800 running watts | 2,200 starting watts

• Home Office (computer, monitor, router): 500 running watts | 500 starting watts

• Television: 300 running watts | 300 starting watts

• Lights: 200 running watts | 200 starting watts

Their total running load is 3,000 watts. The biggest starting surge comes from their refrigerator at 2,200 watts. Their total peak need is 3,000 + 2,200 = 5,200 watts. A 5,500-watt inverter generator is ideal for them, as it provides quiet, clean power that’s safe for their sensitive electronics.

Scenario 3: The Coastal Medical Needs

Finally, let’s visit a retired couple living right on the coast. Their absolute top priority is making sure a critical medical device has uninterrupted power, no matter what. For this family, reliability isn't just a preference—it's non-negotiable.

Their essential load includes:

• Medical Equipment (CPAP): 300 running watts | 300 starting watts

• Refrigerator: 800 running watts | 2,200 starting watts

• Microwave: 1,000 running watts | 1,000 starting watts

• Heating System Fan: 750 running watts | 1,500 starting watts

Their total running need is 2,850 watts. The refrigerator has the biggest startup draw at 2,200 watts. The total starting requirement comes to 2,850 + 2,200 = 5,050 watts.

Because seamless, automatic power is essential for their medical device, they opt for a 10,000-watt (10 kW) home standby generator. This solution offers more than enough power and, crucially, kicks on automatically the moment an outage occurs. It provides the ultimate security.

As you can see, there’s no single right answer—only the right answer for you. For an expert assessment of your home’s unique needs, contact RC Generators and Electric for a free consultation in Los Angeles or Ventura County.

Ensure Your Peace of Mind with a Professional Assessment

At this point, you have the knowledge to make a smart, informed decision about your backup power needs. A DIY calculation gives you a fantastic starting point for figuring out what size generator you need for your house, but ensuring your family's safety and comfort is what really matters.

When it comes to whole-home solutions and guaranteed accuracy, nothing beats a professional assessment.

A licensed expert can do more than just confirm your load calculation. They’ll assess your home's unique electrical setup and ensure the installation is safe and compliant. This is especially true for standby generators, which tie directly into your home's electrical panel and require a deep understanding of electrical systems.

Don't leave your security to chance. A professional evaluation eliminates guesswork, protecting both your valuable appliances and your investment in a new generator.

The Value of an Expert Consultation

An on-site visit from a qualified electrician provides several key benefits that a simple calculation can't offer:

• Code Compliance: An expert makes sure your installation meets all local California electrical codes, preventing headaches down the road.

• System Integration: They’ll map out the best way to connect the generator to your home, including the all-important transfer switch.

• Fuel Line Logistics: For standby units, they plan the safest and most efficient route for natural gas or propane lines.

Ready to secure your home against the next power outage with confidence? Our team of California-based experts is here to help.

To see how we can help, check out our generator installation and electrical services. We'll help you find the perfect generator so you’re prepared for anything.

A Few More Questions About Sizing Your Generator

Even after you've crunched the numbers, a couple of common questions usually pop up. Let's tackle them now so you can feel completely confident about choosing the right generator for your home.

Can I Just Buy a Bigger Generator to Be Safe?

It seems logical, right? Just go bigger and you’re covered. But in reality, buying a generator that’s way too powerful for your needs isn't the best idea. For starters, a much larger unit costs more upfront and uses more fuel, making every outage more expensive than it needs to be.

An oversized generator can also be less efficient when it's consistently under-loaded. This can sometimes cause performance issues over time. It’s always smarter—and more cost-effective—to get a generator that’s a close match for your actual power needs.

How Does Fuel Type Affect My Choice?

The fuel source is a huge deal, especially when you're thinking about long power outages. Gasoline is readily available but can become scarce during a widespread emergency when everyone is trying to get it.

This is where standby generators really shine. Propane and natural gas are far more reliable for California homeowners who might face multi-day shutoffs. Propane can be stored safely for long periods in a large tank on your property. Natural gas is the ultimate in convenience, hooking directly into your utility line for a virtually endless supply.

What About a Transfer Switch? Is it Really Necessary? A transfer switch is the device that safely connects your generator to your home’s electrical panel. If you plan on powering anything that’s hardwired into your house (like your lights or HVAC), it is required by law. It works by completely disconnecting your home from the utility grid before it switches over to generator power. This prevents a dangerous situation called "backfeeding," which can send electricity back down the power lines and seriously injure utility workers.

Don't leave your family’s comfort and safety up to guesswork. For a precise load calculation and a professional installation you can trust, call the experts at RC Generators and Electric. We’re certified to install Generac systems and handle all the electrical work needed to get your home ready for any outage.

Contact us today for a free, no-obligation consultation!