What Size Power Station Do I Need?
List the devices you need to run and for how long, and get a recommended power station capacity in watt-hours.
Daily energy use
1636 Wh
Total needed
1636 Wh
Recommended capacity
2,000 Wh
The recommendation rounds up to the nearest common commercial capacity tier and includes an 85% efficiency margin for inverter and battery losses. It covers steady running watts only — a device with a motor or compressor also needs the power station's surge (peak) rating to cover its brief startup spike, covered in the Surge Watts Calculator.
How the What Size Power Station Do I Need? works
List each device you want to power, its wattage (quick-fill from a common appliance if you're not sure), and how many hours a day you'd run it — then set how many days of backup you want. The calculator totals your daily energy use and recommends a power station capacity.
The recommendation includes a typical 85% usable-efficiency margin and rounds up to the nearest common commercial capacity tier, so you get a realistic model size rather than a theoretical exact number.
Frequently asked questions
Why does the recommendation round up to a specific number like 1,000 or 1,500 Wh?
Power stations are sold in a handful of common capacity tiers rather than every possible watt-hour value, so the tool rounds your calculated need up to the nearest widely available tier, giving you a realistic model size to actually shop for rather than an oddly specific number.
Should I add every device I own, or just the essentials?
For outage planning, most people list only what they'd actually want to keep running during a multi-day outage (a fridge, some lighting, phone charging, medical equipment) rather than every appliance in the house — adding everything usually recommends a far larger, more expensive capacity than most outages actually require.
Does this account for recharging the power station during an outage, like with solar panels?
No — this calculates the capacity needed to run your listed devices for the chosen number of days with no recharging at all, which is the more conservative, safer planning assumption; solar recharging would reduce the capacity actually needed, but depends on weather and panel setup that varies too much to estimate generically here.