Generator Wattage Guide by Appliance
Expert breakdowns for 20 appliances — startup surge, running watts, minimum generator size, and recommended models. Pick any appliance to see the full guide.
Critical Systems
Medical, safety, and flood-prevention loads where 100% uptime is non-negotiable.
Sump Pump (1/2 HP)
2.3kW peakRunning
800W
Startup
2,300W
Min. gen.
3kW
Well Pump (1 HP)
5kW peakRunning
1,500W
Startup
5,000W
Min. gen.
5kW
CPAP Machine
30W peakRunning
30W
Draw
30W
Min. gen.
1kW
Oxygen Concentrator
600W peakRunning
300W
Startup
600W
Min. gen.
1kW
Cooling & Heating
High-surge inductive motor loads — the hardest appliances to size a generator for.
Central AC (3-Ton)
14kW peakRunning
3,500W
Startup
14,000W
Min. gen.
15kW
Window AC (10,000 BTU)
2.5kW peakRunning
1,200W
Startup
2,500W
Min. gen.
3kW
Space Heater (1,500W)
1.5kW peakRunning
1,500W
Draw
1,500W
Min. gen.
2kW
Kitchen
Resistive heating elements and small motors — more predictable, but wattage adds up fast.
Refrigerator / Freezer
800W peakRunning
150W
Startup
800W
Min. gen.
2kW
Coffee Maker
1kW peakRunning
1,000W
Draw
1,000W
Min. gen.
1.5kW
Microwave (Home)
1.5kW peakRunning
1,500W
Draw
1,500W
Min. gen.
2kW
Dishwasher
1.8kW peakRunning
1,200W
Startup
1,800W
Min. gen.
2.5kW
Toaster Oven
1.2kW peakRunning
1,200W
Draw
1,200W
Min. gen.
1.5kW
Laundry & Water
240V appliances and high-draw elements — most need a 240V outlet on your generator.
Tools & Workshop
High-torque motors with extreme startup surges — size up generously for job sites.
Entertainment & Lifestyle
Sensitive electronics requiring clean sine-wave power — inverter generators strongly preferred.
RV & Outdoor
Compact, portable setups where weight, noise, and soft-start solutions matter most.
Running multiple appliances at once?
Our free wattage calculator adds up all your loads simultaneously and tells you exactly what generator size you need — including the startup surge.
Open Wattage Calculator