How many watts does a microwave use
While it runs, a microwave draws 600 to 1,200 W, and it has no starting surge. The smallest portable that can run it comes in at 2,000 W.
Watts while running and at start
| Load | Running | Starting |
|---|---|---|
| Microwave | 600 to 1,200 W | no surge |
These figures come from the Champion wattage chart dated 04-17-26. Your microwave's nameplate shows its exact figure, either in watts or amps. To get watts from amps, multiply by 120 V. Multiply by 240 V only if the load, such as a well pump, runs on a two-pole breaker.
How small a generator can start it
Your generator has to deliver 1,200 W, and that load stays at 80% of its rating or below The smallest common portable size is 2,000 W, and it handles both jobs with room to spare. Every extra load adds its running watts to that same generator.
A microwave alongside other loads
| Microwave plus | Running | Peak at a start | Smallest portable |
|---|---|---|---|
| lights, TV and the router | 1,770 W | 1,770 W | 3,000 W |
| a freezer and lights | 1,850 W | 2,350 W | 3,000 W |
| a 1/2 hp sump pump and lights | 2,400 W | 3,500 W | 3,000 W |
| a 1 hp well pump | 3,200 W | 5,200 W | 5,000 W |
| a window AC, 10,000 BTU | 2,400 W | 3,600 W | 3,000 W |
Running watts add up, and only the biggest motor start sits on top of them. A portable puts out about 25% more at start than its running rating. Every load listed in the appliance wattage chart.