A dishwasher draws about 1,200-2,400 watts while its heater is on and much less while just pumping water; an ENERGY STAR model uses about 1 kWh or less per load. The pump motor has a modest starting surge.
- Running watts
- 1,200 WTypical; 1,200–2,400 W across models
- Starting watts
- 1,500 WPump motor start; generator charts list about 1,500-1,800 W starting
- Per day
- 1 kWh1.5 h of use, cycling
- Current
- 10 AAt 120 V while running
Figures checked against DOE, ENERGY STAR and manufacturer data on . Your model's label is the final word.
Watts by model and setting
Most dishwasher models draw between 1,200 and 2,400 W while running; a typical one draws about 1,200 W. Per load: ENERGY STAR standard models are capped at 240 kWh/yr over 215 cycles (about 1.1 kWh per cycle). The heater runs only part of a 1.5-2 hour cycle: 1,200 W x 1.5 h x 0.55 = ~1 kWh per run. Averaged over the year (215 loads) this is about 0.6 kWh/day.
- Heated dry greatly increases energy use; air dry saves energy
- High-temp, sanitize and heavy cycles heat water more
- ENERGY STAR standard models use at most 240 kWh a year
- Water heater temperature: most dishwashers boost incoming hot water internally
Running a dishwasher on a generator or power station
- Generator: at least 1,200 running watts and 2,700 starting watts (running plus the 1,500 W start surge, the cautious way to size it). Check both numbers on the spec sheet. A generator rated 3,000 W or more covers it with room to spare.
- Power station: continuous output of at least 1,200 W and a surge rating that covers about 1,500 W. Pure sine wave output is the safe choice for motors and electronics.
| Power station capacity | Estimated runtime |
|---|---|
| 500 Wh | 0.6 h |
| 1,000 Wh | 1.3 h |
| 2,000 Wh | 2.6 h |
| 3,000 Wh | 3.9 h |
Based on 660 W average draw (running watts × duty cycle) and 85% usable capacity.
- Wait for the heating phases: brief peaks of 1,200-1,800 W need a 2,000 W+ generator or power station
- Choose an eco or air-dry cycle when running on backup power
- Most dishwashers are hardwired or on a dedicated circuit; powering one needs a transfer switch or interlock, never backfeeding
- Run a gas generator outdoors only, at least 20 feet from doors, windows and vents; carbon monoxide from generators kills. Connect appliances with heavy-duty extension cords or a professionally installed transfer switch, never by backfeeding.
Add it to the generator calculator
Questions people ask
How much electricity does a dishwasher use per load?
About 1 kWh or less for an ENERGY STAR model, more with heated dry or sanitize cycles.
Can I run my dishwasher on a generator?
Yes with a 2,000-3,000 W generator through a transfer switch, but it is usually low priority during an outage.
Sources
- ENERGY STAR: Dishwashers key product criteria
- ENERGY STAR: Dishwashers
- Virginia Cooperative Extension (developed with U.S. DOE): Estimating appliance and home electronic energy use
- Honda Power Equipment: Generators guide with appliance wattage chart (PDF)
- Champion Power Equipment: Generator wattage chart (PDF)