Picking the right size generator for your RV boils down to one critical task: calculating the total power you need to run your appliances simultaneously, with special attention to your air conditioner. To do this correctly, you must understand the difference between running watts (the continuous power an appliance uses) and starting watts (the temporary surge of power needed to start motors).
As a general rule, a 2,200 to 3,500-watt inverter generator is sufficient for smaller campers and most travel trailers aiming to run a single A/C unit and basic appliances. For larger Class A motorhomes with multiple air conditioners and residential appliances, you'll likely need 4,000 watts or more.
Finding Your Perfect RV Generator Size
Choosing a generator is a key decision for any RVer. It provides the freedom to camp off-grid without sacrificing essential comforts like air conditioning or a morning coffee. The good news is you don’t need an electrical engineering degree to figure out the right size.
This guide will walk you through the practical steps to calculate your power needs and choose a generator with confidence.
The process starts with identifying your single most power-hungry appliance, which is almost always the air conditioner. The massive surge of energy it needs to start its compressor is the single biggest factor determining the minimum size of your generator.
Matching Generator Size to Your RV
To give you a head start, I've put together a quick-glance table. Think of this as a solid starting point before you dive into calculating your own specific needs. It lines up common RV types with the generator sizes that usually work best for them, helping you immediately get a feel for what you might be looking for.
Quick Guide To RV Generator Sizes
This table offers a snapshot of typical generator recommendations for different RVs. Use it to get a general idea, but always remember to calculate your specific needs, especially if you have an upgraded AC unit or other high-demand appliances.
| RV Type | Recommended Generator Size | Typical Appliances Powered |
|---|---|---|
| Small Campers & Pop-Ups | 2,200 – 3,000 watts | A/C (up to 13,500 BTU), microwave, lights, small electronics, fridge. |
| Travel Trailers & Fifth Wheels | 3,000 – 4,500 watts | A/C (up to 15,000 BTU), microwave, TV, coffee maker, fridge, lights. |
| Class A & Large Fifth Wheels | 4,500+ watts | One or two A/C units, residential fridge, TV, all kitchen appliances. |
This should give you a good ballpark idea. Your personal setup might be a little different, but for most folks, these numbers are right on the money.
The growing desire for reliable off-grid power has made the generator market pretty robust. Back in 2023, the market for RV generators was valued at around USD 1.85 billion. Generators are typically broken down into low power (under 3 kW), medium power (3 to 6 kW), and high power (over 6 kW) models. This variety means there’s a unit out there that perfectly matches what you need. If you're interested in the market trends, you can find more insights on DataHorizzon Research.
Key Takeaway: Don't just add up the running watts of all your appliances. Your generator has to be powerful enough to handle the single biggest startup surge (usually your A/C), plus the running watts of everything else you want to use at the same time.
The Difference Between Running and Starting Watts
Before picking a generator, you must understand one fundamental concept. Getting this wrong is the primary reason RVers buy an undersized generator, and it all comes down to the critical difference between running watts and starting watts.
Appliances with motors—especially your air conditioner, microwave, and refrigerator—require a large initial burst of energy to get started.
That initial, powerful burst is the starting wattage, sometimes called surge wattage. It's a massive, temporary spike of power an appliance needs for just a few seconds to kick its motor into gear. The steady, lower energy draw required for continuous operation is the running wattage.
Why This Initial Surge Is So Important
Every generator has two power ratings: a higher number for starting watts and a slightly lower one for running watts. The most power-hungry beast in your rig is almost always the air conditioner—typically a 13,500 BTU or 15,000 BTU unit. This single appliance is what dictates your minimum generator size.
While that A/C might only use 1,500 watts to run, it can demand a massive surge of 2,800 to 3,500 watts just to start up.
This brief but powerful startup demand is the entire reason a 2,200-watt generator, which seems like it should be more than enough on paper, often can't start a standard RV air conditioner. The generator simply can't provide that initial punch and will shut itself down or trip its breaker.
Understanding this changes everything. You’re not just shopping for a generator that can handle the continuous load; you need one that can absorb the single biggest power punch from your most demanding appliance.
A Practical Example of Starting vs. Running Watts
Let's walk through a common scenario to see how this plays out in the real world:
- Appliance: A standard 13,500 BTU RV Air Conditioner.
- Running Watts: It needs about 1,500 watts to keep you cool once it's up and running.
- Starting Watts: To fire up its compressor, it needs a momentary jolt of roughly 2,800 watts.
This means your generator must be able to produce at least 2,800 watts for those few crucial seconds. If your generator is only rated for 2,500 starting watts, that A/C will fail to start every single time, leaving you sweating. When you calculate your power needs, always solve for that peak starting demand first.
How to Calculate Your Actual RV Power Needs
Now that you know the critical difference between running and starting watts, it’s time to calculate your RV's specific power requirements. This isn’t about guesswork; it’s a simple, practical process to determine the exact generator size for your camping style.
Following these three steps will ensure you make an informed decision and avoid buying a generator that is either too small or unnecessarily large.
Big names like Cummins, Westinghouse, and Honda all offer great options, but picking the right model starts with knowing your numbers. For a deeper dive into the market, Grand View Research offers some interesting insights.
Step 1: List Your Must-Have Appliances
First, grab a notepad or open a note-taking app. Think about a typical camping scenario. What appliances do you absolutely need to run at the same time?
Be realistic. You’re probably not going to run the microwave, coffee maker, and a hair dryer all at once. A much more common scenario is having the air conditioner running while someone watches TV and the fridge cycles on in the background.
Your "must-have" list might look something like this:
- Air Conditioner (13,500 BTU)
- Refrigerator
- Television
- Microwave (for those quick popcorn moments)
- Coffee Maker
- Lights
- Phone Chargers
Step 2: Find the Wattage for Each Item
Next, find the running and starting watts for everything on your list. The most accurate numbers are found on the appliance's data plate or in the owner's manual.
If you can’t find the exact figures, this chart provides solid estimates for common RV appliances.
Common RV Appliance Wattage Chart
| Appliance | Typical Running Watts | Typical Starting Watts |
|---|---|---|
| RV Air Conditioner (13,500 BTU) | 1,500 | 2,800 – 3,500 |
| RV Air Conditioner (15,000 BTU) | 1,800 | 3,500 – 4,000 |
| Microwave (1000-watt) | 1,500 | 2,000 |
| Refrigerator | 600 | 1,200 |
| Coffee Maker | 1,000 | 0 |
| Television | 150 | 0 |
| Interior Lights (LED) | 20 | 0 |
| Phone Charger | 10 | 0 |
You’ll notice some items, like your coffee maker or TV, have zero starting watts. That's because they don't have motors that need that big initial jolt of power to get going.
Step 3: Tally Your Total Power Demand
This is where you calculate your total wattage requirement. The formula is simple, but it's crucial to follow it correctly.
Your Total Power Needs = (Highest SINGLE Starting Watts) + (Sum of all other Running Watts)
Do not add up all the starting watts. This is a common mistake that leads to buying an oversized and overpriced generator. Your appliances almost never start at the exact same millisecond, so you only need to account for the single biggest power surge, which is almost always the air conditioner.
Let's walk through a real-world example. Say you want to run your 13,500 BTU A/C, the refrigerator, and the TV at the same time.
- Identify Highest Starting Wattage: The A/C is the most demanding appliance, requiring 3,000 watts to start.
- Add Running Watts of Other Appliances: Add the running watts of everything else you plan to use simultaneously: 600 (Fridge) + 150 (TV) = 750 Running Watts.
- Calculate Your Total: 3,000 (A/C Starting) + 750 (Other Running) = 3,750 Total Watts
In this scenario, you’d need a generator with at least 3,750 starting watts to handle that load without issue. A 4,000-watt generator would be a safe and reliable choice.
Real-World Sizing Scenarios for RV Owners
Calculations are helpful, but seeing how they apply to real-world camping situations makes the concept much clearer. Let’s look at three different RVers to see what size generator best fits their specific needs.
These scenarios will help you align your own setup with a practical solution, whether you're a minimalist boondocker, a weekend adventurer, or a full-time traveler.
Getting the right size generator starts with a basic list and ends with a clear number for your total power demand.
Scenario 1: Boondocking Bill's Camper Van
Bill enjoys off-grid camping in his van and has minimal power needs. He just needs to keep his laptop charged, run a small fan at night, and keep his phone topped off. He has no air conditioner or microwave.
- Laptop Charger: 65 running watts
- Small Fan: 50 running watts (with a tiny 100-watt startup surge)
- Phone Charger: 10 running watts
Bill’s total running load is only 125 watts. The fan’s startup requirement is negligible. For him, a small, portable 1,000-watt generator is more than enough, providing quiet, fuel-efficient power for his minimalist setup.
Scenario 2: The Wilsons' Weekend Travel Trailer
The Wilson family loves their weekend trips in their travel trailer. Their main priority is running their 13,500 BTU air conditioner. They also want to use the microwave and keep the refrigerator running.
Here’s their power calculation:
- Highest Starting Watts: The A/C needs about 3,000 starting watts.
- Other Running Loads: They might run the fridge (600 watts) and microwave (1,500 watts) at the same time. While they likely wouldn't start the A/C and microwave simultaneously, they need to ensure the generator can handle the A/C starting while the fridge is already running.
- Total Demand Calculation: 3,000 (A/C Starting) + 600 (Fridge Running) = 3,600 watts.
To handle the A/C's initial power surge while the fridge is running—and still have enough juice left for the microwave—they need a generator that can pack a punch. A generator in the 3,500 to 4,500-watt range is the perfect fit for them.
Scenario 3: Full-Time Frank's Class A Motorhome
Frank lives full-time in his Class A motorhome and needs to power multiple high-draw appliances, often at the same time, including two 13,500 BTU air conditioners.
His typical power needs look something like this:
- Two 13,500 BTU A/C units (3,000 running watts total)
- Residential Refrigerator (600 running watts)
- Television (150 running watts)
To start one of his A/C units while the other one is already running, he'll need 3,000 starting watts on top of the running load of everything else. That puts him squarely in the 5,500-watt range. To reliably start both air conditioners and keep his other appliances happy, Frank needs a beefy generator of at least 6,000 watts, the kind you typically find in onboard models.
As you can see, your camping style—from barebones boondocking to full-time luxury—is the biggest factor in sizing your generator. If you're interested in a broader look at the generator market, Precedence Research offers some great industry insights.
Why an Inverter Generator Is Best for Camping
Once you've determined your wattage needs, the next step is choosing the type of generator. Many new RVers mistakenly purchase cheap, powerful "construction-site" generators, which are unsuitable for camping due to noise and power quality.
For virtually every RVer, the best choice is an inverter generator. The differences in noise, fuel efficiency, and power quality are significant.
The Dimmer Switch Analogy
A conventional generator is like a basic light switch—it's either all the way on or all the way off. Its engine must run at a constant high speed (typically 3600 RPM) to produce power, regardless of the load. This makes it extremely loud and inefficient.
An inverter generator acts more like a dimmer switch. It uses sophisticated electronics to adjust its engine speed to precisely match the power being drawn. This intelligent design provides major benefits for camping.
An inverter generator produces what we call "clean" power, or a pure sine wave. This stable, consistent electricity is crucial for safely running sensitive modern electronics like laptops, smartphones, and TVs. Conventional generators produce "dirty" power with voltage spikes that can easily fry those delicate circuits.
Quieter Operation for Happier Neighbors
The most noticeable benefit of an inverter is its quiet operation. Because the engine can slow to an idle under light loads, it is dramatically quieter. A typical inverter generator runs between 50 and 60 decibels, comparable to a normal conversation.
A conventional generator, roaring at full throttle, often exceeds 70 decibels. This is not only disruptive but will also violate the noise regulations of most campgrounds. National parks and private campgrounds enforce quiet hours and strict decibel limits. Choosing an inverter is a matter of good campground etiquette.
Fuel Efficiency and Lighter Weight
The "dimmer switch" technology also makes an inverter far more fuel-efficient. By running at lower RPMs for smaller loads, it can be 20-40% more fuel-efficient than a conventional model of the same size. This means you carry less fuel, spend less money, and can extend your off-grid stays.
Finally, inverter generators are designed for portability. They are almost always much smaller and lighter than their conventional counterparts, making them easier to handle and store. For camping applications, an inverter generator is the clear choice.
Important Features Beyond Generator Wattage
Knowing your wattage needs is the first step, but selecting the right what size generator for rv also involves considering features that impact your daily camping experience. These practical details often distinguish a generator you love from one you regret buying.
Choosing a generator based only on watts is like buying a car based only on its horsepower. You've got to consider how you'll actually use it on the road. Let's break down the key features that will really impact your experience.
Fuel Type: Gasoline vs. Propane
The first big decision is what you'll be putting in the tank. For portable models, the two most common options are gasoline and propane, and each has its own clear advantages for RVers.
- Gasoline: The traditional choice, gasoline provides the most power output for a given generator size and is widely available. However, it has a short shelf life and storing extra cans of gasoline can be a safety concern.
- Propane: Many RVers prefer propane because it's already onboard for other appliances. It has an indefinite shelf life in the tank and burns cleaner, which reduces engine maintenance. The trade-off is that propane is less energy-dense, so generators produce about 10% less power when running on it.
A dual fuel generator offers the best of both worlds, providing the flexibility to use whichever fuel is more convenient.
Noise Level and Weight
A generator's noise level, measured in decibels (dB), is a critical factor for camping. A loud generator can ruin the peace of a campsite and violate campground rules. Look for modern inverter generators that operate in the 50-60 dB range, which is about the volume of a normal conversation.
Weight is another major consideration. A "portable" generator isn't very useful if it's too heavy to move easily. If a single 4,000-watt unit is too cumbersome, consider a parallel kit with two smaller 2,200-watt generators. This setup provides up to 4,400 watts when linked together but allows you to lift and move each lighter unit individually.
Pro Tip: Parallel capability offers incredible flexibility. You can use a single, quiet generator for light-duty stuff like charging phones, and only fire up the second one when it's time to blast the air conditioner. This saves a ton of fuel and keeps the noise to an absolute minimum.
Your RV Generator Questions, Answered
Now that you have the fundamentals, let's address some of the most common questions from fellow RVers.
Can I Really Run My RV Air Conditioner With a 2000-Watt Generator?
The short answer is usually no. While a smaller A/C unit may only use 1,500 running watts, its starting watts can easily exceed 2,500-3,000 watts. A 2,000-watt generator cannot handle this initial surge and will trip its breaker.
However, there is a practical solution: installing a soft starter on your AC unit. This device reduces the initial power surge by up to 75%. With a soft starter installed, a high-quality 2,200-watt generator can often successfully start and run a standard 13,500 BTU air conditioner.
What Exactly Is a Parallel Kit and Do I Need One?
A parallel kit is a special cable that allows you to connect two compatible inverter generators to combine their power output. For example, linking two 2,200-watt generators gives you a total of 4,400 watts.
This provides significant flexibility. You can use one lightweight generator for minimal power needs like charging devices, and then connect the second unit only when you need to run high-draw appliances like the air conditioner. This makes handling and storage much easier than dealing with a single, heavy 80-100 pound generator.
A parallel setup is my go-to recommendation for RVers who want enough power for their A/C but don't want the backache that comes with a single, heavy unit. It’s all about having flexible power when you need it.
Propane vs. Gas Generators: Which One Is Better?
The best choice depends on your priorities. Propane is convenient because it can often be hooked directly into your RV's onboard tanks, burns cleaner, and won't degrade in storage.
The trade-off? Propane is a bit less energy-dense, so you'll get about 10% less power out of it compared to gasoline. Gas is everywhere, but it can degrade and gum up your carburetor if it sits too long. For my money, a dual fuel generator offers the best of both worlds. It gives you the ultimate freedom to use whatever fuel is available or convenient at the moment.
From parallel kits to tune-up supplies, RVupgrades.com has all the generator accessories you need to keep your adventures powered up. Explore our full selection of electrical and solar products today!
