RV camping tool · Portable power
RV Generator Size Calculator
Add the appliances you expect to run together and the largest motor startup surge.
Updated 2026-08-12
Running watts and startup watts are different
A generator must support the appliances running together and the highest plausible motor-compressor startup event. Air conditioners, refrigerators, pumps and some tools can briefly draw well above their continuous rating.
30 amp vs 50 amp RV service
| Service | Theoretical shore-power capacity | Generator implication |
|---|---|---|
| 30 amp, 120 V | 3,600 W | A smaller generator may run selected loads, not necessarily everything together |
| 50 amp, split 120/240 V | 12,000 W total | A portable generator rarely reproduces full pedestal capacity |
Operate generators safely
- Use only outdoors, far from doors, windows and vents.
- Never run a generator in an RV, compartment not designed for operation, tent, garage or enclosed shelter.
- Use a working carbon-monoxide alarm and follow the generator and RV manuals.
- Confirm plug, adapter, neutral/ground and transfer-equipment compatibility.
Frequently asked questions
What size generator do I need for a 30 amp RV?
A 30 amp RV can theoretically use up to 3,600 watts at 120 volts, but the required generator depends on which appliances run together and their startup surges.
Will a 2,000 watt generator run an RV air conditioner?
Sometimes, but compressor startup can exceed the generator surge rating. Check the air-conditioner nameplate, soft-start equipment requirements and generator rating.
Can a generator fully power a 50 amp RV?
Full 50 amp RV service can provide up to 12,000 watts across two legs. Many portable generators supply much less, so load management is required.
Related tools and guides
Official sources
Rules and penalties change. Confirm your situation with the issuing authority or a qualified professional before acting.