Portable Power Station Runtime Calculator
Find out how long a power station will run your devices, and what size you really need.
⚡ Portable Power Station Runtime Calculator
Tick the devices you need, set hours per day, and see what size portable power station you need.
0 WRunning at the same time
0 WhEnergy needed per day
–Runtime on your power station
Select at least one device to get a recommendation.
Estimates assume 85% usable capacity and typical device wattage. Check your device’s label for exact watts.
How to use the calculator
- Tick every device you want to power at the same time.
- Adjust the hours per day each device runs.
- Enter your power station’s capacity in watt-hours (Wh) to see its estimated runtime.
- Use the recommended capacity and output to shortlist models.
The formula
Runtime (hours) = capacity (Wh) × 0.85 ÷ device watts. The 0.85 factor accounts for inverter losses. For devices that cycle on and off, like refrigerators, use the average watts (kWh per year from the energy label ÷ 8,760).
Recommended sizes
| Daily energy need | Recommended size | Typical uses |
|---|---|---|
| Under 600Wh | 300–700Wh | Phones, laptops, lights, one CPAP night |
| 600–1,100Wh | 1,000–1,300Wh | Camping weekends, CPAP for 2–3 nights |
| 1,100–1,900Wh | 1,500–2,300Wh | RV trips, a fridge plus essentials for most of a day |
| 1,900–3,300Wh | 3,000Wh+ | Home backup for a full day |
| Over 3,300Wh | Expandable 5kWh+ plus solar | Multi-day outages, off-grid cabins |
See our top-rated models in our best portable power station guide.