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Generator size calculator

INVERTER110Generator Size Calculator
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Panel-rated sizing tool

What size
generator
do you need?

Add the appliances you want to run, and get the minimum generator rating in watts, kW, kVA and amps — built for electricians, homeowners, contractors and RV owners across the US.

Required Generator -- kW
Step 1–3

Build your load list

Search the appliance database or add your own equipment with its exact running and starting watts, then review your recommended generator size in the panel on the right.

Appliance database

Your load list

ApplianceRunning WStarting WQty
No appliances added yet. Search above or add a custom item below.

Add custom appliance

Advanced options

Recommended generator

Total running watts
0 W
Peak starting watts
0 W
Recommended generator size
0 W
0 kW · 0 kVA · 0 A
Portable
Safety margin
25%
Est. fuel use / hr
0.0
gal/hr at ~50% load
Est. runtime on a 5-gallon tank
-- hrs
Running load, starting load and recommended generator capacity, in watts.
Reference guide

Generator sizing, explained

Everything behind the numbers above — how the math works, what running and starting watts actually mean, and how to pick the right generator for your home, jobsite or RV.

FAQ

Frequently asked questions

The questions we hear most from homeowners, electricians and RV owners sizing a generator for the first time.

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© 2026 Inverter110. Estimates are for planning purposes only — consult a licensed electrician before sizing or installing a generator.