Appliance wattage chart
Typical running and starting watts for common household appliances, for sizing a generator or power station.
Short answer
Most kitchen and comfort appliances draw 500 to 1,500 W while running. Anything with a motor, like a refrigerator, sump pump or AC, needs two to three times its running watts for a few seconds when it starts. Electronics such as routers, laptops and CPAP machines draw under 100 W.
The chart
| Appliance | Running watts | Starting watts | Voltage |
|---|---|---|---|
| Box fan | 60 | 60 | 120 V |
| CPAP machine (no heated humidifier) | 40 | 40 | 120 V |
| Central AC (3 ton) | 3,500 | 10,000 | 240 V |
| Chest freezer | 80 | 600 | 120 V |
| Coffee maker | 900 | 900 | 120 V |
| Dehumidifier (50 pint) | 500 | 700 | 120 V |
| Electric kettle | 1,500 | 1,500 | 120 V |
| Electric water heater | 4,500 | 4,500 | 240 V |
| Garage door opener (1/2 HP) | 875 | 2,350 | 120 V |
| Gas furnace blower (1/2 HP) | 800 | 2,350 | 120 V |
| Home oxygen concentrator | 350 | 350 | 120 V |
| LED light bulb (10 W) | 10 | 10 | 120 V |
| Laptop | 60 | 60 | 120 V |
| Microwave (1,000 W cooking power) | 1,500 | 1,500 | 120 V |
| Phone charging | 10 | 10 | 120 V |
| Refrigerator (full size, Energy Star) | 150 | 1,200 | 120 V |
| Space heater | 1,500 | 1,500 | 120 V |
| Sump pump (1/2 HP) | 1,050 | 2,150 | 120 V |
| TV (55 inch LED) | 100 | 100 | 120 V |
| Washing machine | 500 | 1,400 | 120 V |
| Well pump (1/2 HP) | 1,000 | 2,100 | 240 V |
| Wi-Fi router and modem | 20 | 20 | 120 V |
| Window AC (10,000 BTU) | 900 | 2,200 | 120 V |
Running watts vs. starting watts
Running watts are what an appliance draws once it is up and running. Starting watts are the brief surge a motor or compressor pulls in the first second or two. Heaters, kettles and microwaves have no real surge, so both numbers are the same.
When sizing backup power, add up the running watts of everything on at once, then add the largest single surge. The generator size calculator does this for you.
Why your appliance may differ
These are typical values for US appliances. Age, size, efficiency rating and motor type all change the real draw. Newer inverter-drive refrigerators and heat pumps often have much smaller startup surges than older models.
To get your own numbers, check the rating plate (usually listed in amps; multiply amps by 120 for watts), or measure with a plug-in watt meter. The meter is more accurate, because the label shows the maximum, not the typical draw.
Watts over time
For batteries, total energy matters more than peak watts. A refrigerator rated at 150 W that runs about 9 to 10 hours a day uses around 1.4 kWh daily. The runtime calculator uses hours per day to turn wattage into realistic battery life.
Sources and method
Runtime figures assume 85% of battery capacity reaches AC appliances and typical US appliance ratings. See exactly how we calculate. Found a mistake? Tell us and we will fix it.