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What Size Generator Do I Need for My RV? Things to Know!

Written by Philip Lopez / Fact checked by Paul Lemaire

what size generator do i need for my rv

I wanted to bring as many appliances as possible to my next boondocking but was a bit confused about what size of generator to get for my camper. Generally, we’d want the right generator size to ensure that we can safely run our appliances. So, what size generator do I need for my RV?

If you have the same concern, it depends on the appliances that you’re planning to use for camping. Get the wattage rating of each appliance, both starting and running, then add them all together. Find a generator that’s a bit higher than the total amount.

Let us delve into this matter more deeply below.

Table of Contents

Common Generator Sizes for Each Type of RV


If you like a quick estimate on what size generator you need for your RV, you can refer to its type. Keep in mind that these ranges could change, depending on what appliance you use in your camper.

  • Class A:

A Class A motorhome typically needs a generator size of 5,000 to 7,000 watts. This range could power several heavy appliances, such as an air conditioner (AC), dishwasher, and coffee maker with no problem.

  • Class B

Smaller than most RVs, Class B motorhomes generally need 2,000 to 3,600 watts of generator size. This size could run one AC unit along with a few small electrical devices like a TV, radio, and gaming console.

  • Class C

An average-sized Class C motorhome usually uses 3,500 to 5000 watts of generator size. This amount of electricity can run multiple appliances, including one AC unit, washing machine, and microwave.

  • Fifth Wheel

A generator for 5th wheel should provide power between 3,500 and 7,000 watts. If your vehicle has a permanent generator, this type is more convenient than its portable counterparts because it starts with a button. No more going outside to fire up the generator in the cold.

How Much Wattage Your RV Really Needs

One way to know the exact size generator to run a camper is to know how much power you need. This means summing up all the wattages your appliances draw at one time.

The best place to find the exact power draw of every appliance is the product label or manual. If it’s expressed in amps, use the formula watt = amp x volt.

Here’s a chart showing the approximate wattage of some common RV appliances.

Appliance Starting Watts Running Watts
Portable fan 120 40
Air conditioner, 15,000 BTU 3,300 2,000
RV Refrigerator 600 180
Microwave oven, 650 watts 1,000 1,000
Flat-screen TV (20-inch) 120 120
Total 5,140 3,340

Take note that appliances with electric motors draw more watts during startup than during their normal operation. Motorless devices, like TVs, only require a smaller amount of electricity.

To determine how many watt generator for RV, get a number higher than your total watts.

Let’s say for a travel trailer that uses a total of 5,140 starting watts and 3,340 running watts, get a generator with a size of 5,200 watts or more. You’ll need that extra watt to make way for any power surges.



What size generator is good for a 30 amp RV?

If you consider portability and cost, you can do well with a 3000-watt generator for 30 amp RV. This rating is enough to power a 13,500-BTU AC unit. When you run the AC, you’re probably not running any more appliances besides an LED light.

If you like to max out the capacity of your 30-amp RV, you can go with a 3,600-watt generator. That number is derived from the computation of 120 volts x 30 amps.

If you can find a lighter 2,000-watt model, you can make a parallel connection of two units to produce 4,000 watts of generator power.

Furthermore, explore this article to know everything about generators for 30 amp RV (wattage, noise Level, fuel type and more)

What size generator do I need for a 50-amp RV?

A 50-amp RV provides more power than its 30-amp counterpart. If we try to get the maximum capacity (volts x amps), it would be 6,000 watts. Now, this type has two individual 50-amp feeds, providing a higher capacity of 12,000 watts.

With that number, it’s safe to presume that 12,00o-12,500 watts are the ideal size generator for 50 amp RV. It’s not cost-effective to go more than 12,500 watts.

A 3,500-watt generator is often the least you can use for 50-amp RVs. This rating would be enough to operate basic appliances, such as a TV, refrigerator, and AC. To increase capacity with minimal extra weight and cost, consider a parallel connection of two 3,500-watt generators.

How big of a generator size do I need to run an RV air conditioner?

Air conditioners need the most amount of power to run in your RV. Running a single AC requires a generator size of 2,000-4000 watts. For RV with 2 AC units, it needs a generator size of 5,500 to 8,000 watts to ensure smooth operation.

Get a higher capacity if you plan to use other appliances along with an AC unit. You don’t want to sacrifice your favorite TV show for an endless operation of your AC, especially during summer.

What size generator for 25 foot travel trailer?

Usually, if you run an AC unit on this vehicle, you can go for a generator size of 2,500-4,000 watts. If not, a lower capacity of 2,000 watts may do well. That said, you can go higher (5,000W or more) if the wattage of your appliances is higher.


Determining “what size generator do I need for my RV” is easy if you know the maximum watts you’re running in your camper. Check the product label of every appliance and consult the manufacturer if you can’t find the specs. Try to get a generator with a higher number to prevent power shortage.

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