Add the appliances you want to run at the same time, set how many hours each one runs, and the calculator adds up what they need. It then lists the portable power stations and generators we rank that can carry that load, best rated first. Each wattage is filled in from a published chart and can be changed to match the label on your own appliance.
How the calculator works
- Running watts is the total of everything you add, as if it all runs at once. Your power station’s AC output or your generator’s running watts must be at least this.
- Starting watts is the running total plus the extra surge of the one appliance with the largest motor start (a fridge, pump, air conditioner or power tool). Two motors rarely start in the same instant, so only the biggest surge is added. A power station’s surge rating or a generator’s starting watts must cover it.
- Energy is each appliance’s watts times its hours, added up. It matters only for a power station, which stores a fixed amount. A generator runs as long as it has fuel.
- Usable capacity: a power station delivers less than its rated watt-hours through its AC outlets, because the inverter and battery management use some. Where independent tests have measured a model, the calculator uses that model’s measured figure; for the rest it uses 84%, the average of the 67 models with measured results in our power station rankings.
- Fridges and freezers don’t run their compressor all the time. Enter the hours it actually runs, or work from the yearly kWh on its EnergyGuide label (divide by 365 for a day).
- 240 V appliances (central air, an electric dryer or water heater) are left out, because most power stations and many portable generators can’t power them.
Appliance wattage chart
These are the starting presets, as ranges. The calculator fills in the top of each range so it doesn’t come up short. “None extra” means the appliance needs no extra watts to start.
| Appliance | Running watts | Starting watts |
|---|---|---|
| Kitchen | ||
| Refrigerator | 150–400 W | 800–1,200 W |
| Freezer | 100–500 W | 500–1,000 W |
| Mini fridge or cooler | 50–100 W | 400–600 W |
| Microwave | 600–1,200 W | None extra |
| Electric range (one burner) | 1,200–2,400 W | None extra |
| Portable induction cooktop | 1,200–1,800 W | None extra |
| Electric grill | 1,650 W | None extra |
| Electric smoker | 800–1,200 W | None extra |
| Blender | 300–600 W | 600–1,200 W |
| Dishwasher | 1,200–2,400 W | None extra |
| Heating, cooling and water | ||
| Window AC (5,000 BTU) | 450–600 W | 900–1,200 W |
| Window AC (10,000 BTU) | 900–1,200 W | 1,800–2,400 W |
| Furnace fan (1/2 HP) | 300–800 W | 800–1,600 W |
| Space heater | 750–1,500 W | None extra |
| Window fan | 50–200 W | None extra |
| Box fan | 50–200 W | None extra |
| Ceiling fan | 15–75 W | None extra |
| Sump pump (1/3 HP) | 500–800 W | 1,000–1,600 W |
| Sump pump (1/2 HP) | 800–1,050 W | 1,300–2,150 W |
| Well pump (1/2 HP) | 750–1,000 W | 1,500–2,000 W |
| Well pump (1 HP) | 1,000–2,000 W | 2,000–4,000 W |
| Washing machine | 500–1,000 W | 1,000–2,300 W |
| Electronics and medical | ||
| CPAP (no heated humidifier) | 30–60 W | None extra |
| CPAP (heated humidifier) | 60–120 W | None extra |
| Phone or laptop charger | 20–100 W | None extra |
| TV (32 to 55 in) | 80–400 W | None extra |
| Internet router or modem | 10–20 W | None extra |
| Home security system | 15–40 W | None extra |
| LED light bulb | 8–15 W | None extra |
| LED string or camp lights | 50–200 W | None extra |
| Portable projector | 100–300 W | None extra |
| RV and camping | ||
| RV refrigerator | 150–600 W | 400–1,000 W |
| RV air conditioner (13,500 BTU) | 1,500–2,000 W | 2,800–3,500 W |
| RV air conditioner (15,000 BTU) | 2,000–2,500 W | 3,500–4,500 W |
| RV microwave | 600–1,200 W | None extra |
| RV water heater | 1,200–1,500 W | None extra |
| Tools | ||
| Circular saw (7-1/4 in) | 1,200–1,800 W | 2,400–3,600 W |
| Miter saw (10 in) | 1,200–1,800 W | 2,400–3,600 W |
| Table saw (10 in) | 1,800–3,000 W | 3,600–6,000 W |
| Electric drill (1/2 in) | 400–600 W | 800–1,200 W |
| Angle grinder (4-1/2 in) | 900–1,800 W | 1,800–3,600 W |
| Air compressor (1 HP) | 1,500 W | 4,500 W |
| Pressure washer (1,500 PSI) | 1,200–1,500 W | 2,400–3,000 W |
| Power tool battery charger | 25–100 W | None extra |
| Welder (120 V) | 1,800–2,500 W | 3,600–5,000 W |
Source: Champion Power Equipment, Generator Wattage Chart, read November 10, 2026.
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