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What size generator do I need to run a refrigerator and a window AC?

This is the classic summer-outage combination: keep the food cold and one room livable. The math below assumes a full-size fridge and a mid-size 8,000 BTU window unit, plus lights and phone charging because in practice you'll want those too.

The load

SIZING PLATE4 LOADS · +25% HEADROOM
Total running watts
1,140 W
Peak (largest start)
2,540 W
Buy at least
1,450 W rated
Look for ~1,450W running / 2,550W surge or better.

Field note: Let the AC compressor start first, alone, then add the fridge. Two compressors starting simultaneously is how people overload a generator that is technically big enough.

Right size: Mid-size inverter (3,500W / 4,000W surge)

Typical price $600-1,400 · e.g. Champion 4250 open-frame inverter, Westinghouse iGen4500, Generac GP3500iO

RV 13,500 BTU AC (especially with soft-start), fridge + window AC, storm essentials for smaller homes. The sweet spot of quiet, portability, and real capacity for most first-time buyers.

See current prices on Amazon

One size up: Mid-size portable (6,500W / 8,100W surge)

Typical price $700-1,200 · e.g. Westinghouse WGen6500, Champion 6250, Generac GP6500

Storm essentials with margin: fridge, freezer, sump pump, furnace fan, well pump (240V models), lights and electronics together. Louder open-frame design; electronics prefer models with THD under 5% or an inverter.

See current prices on Amazon

Adjust for your setup

Different fridge? Bigger AC? Uncheck and re-check below — the plate recomputes live.

SIZING PLATE4 LOADS · +25% HEADROOM
Total running watts
1,140 W
Peak (largest start)
2,540 W
Buy at least
1,450 W rated
Look for ~1,450W running / 2,550W surge or better.

Peak assumes your largest motor starts while everything else runs — the honest worst case. Start big motors one at a time and a smaller unit may cope, but this number won't let you down.

Kitchen
Heating & cooling
Pumps & well
Electronics
Medical & safety
Lighting
Laundry
Household
Tools & outdoor
RV & camping

Generators that fit

Right size: Mid-size inverter (3,500W / 4,000W surge)

Typical price $600-1,400 · e.g. Champion 4250 open-frame inverter, Westinghouse iGen4500, Generac GP3500iO

RV 13,500 BTU AC (especially with soft-start), fridge + window AC, storm essentials for smaller homes. The sweet spot of quiet, portability, and real capacity for most first-time buyers.

See current prices on Amazon

One size up: Mid-size portable (6,500W / 8,100W surge)

Typical price $700-1,200 · e.g. Westinghouse WGen6500, Champion 6250, Generac GP6500

Storm essentials with margin: fridge, freezer, sump pump, furnace fan, well pump (240V models), lights and electronics together. Louder open-frame design; electronics prefer models with THD under 5% or an inverter.

See current prices on Amazon
This site earns commissions from qualifying purchases made through links to Amazon and other retailers, at no extra cost to you. Wattage figures are typical estimates — actual draw varies by model. Always verify against your appliance's nameplate, and consult a licensed electrician for any panel or hardwired connections.