Sizing calculator

How much backup power do you need?

Choose your devices, a backup window, and what you are planning for. Advanced electrical controls are optional.

POWER NEEDS

Example planning values — edit them to match your actual devices.

DEVICE 1
Source: U.S. Department of Energy appliance tableUses a 50% cycling duty-cycle planning assumption. The 1,500 W startup value is a conservative 3× allowance, not a universal appliance specification. Verify the nameplate or manufacturer documentation.
DEVICE 2
Source: U.S. Department of Energy appliance tableUses a 50% cycling duty-cycle planning assumption. The 1,500 W startup value is a conservative 3× allowance, not a universal appliance specification. Verify the nameplate or manufacturer documentation.
DEVICE 4
Source: ENERGY STAR certified light-fixture listingExample certified LED fixture value; edit this to match the wattage printed on each lamp.
DEVICE 5
Source: U.S. Department of Energy appliance tableInput draw can exceed advertised cooking power; verify the appliance nameplate.
LOAD SUMMARY
Devices selected
7
Estimated energy
4,650 Wh
After conversion losses
5,471 Wh
Recommended rated capacity
~6,437 Wh+
Maximum simultaneous load
1,029 W
Startup / surge requirement
2,029 W

Energy uses each row’s runtime, quantity, and duty cycle. Output sums checked devices; unchecked devices are treated as one-at-a-time loads. Startup replaces that device’s running draw during its start event.

YOUR ESTIMATED NEED
Battery size
~6.4 kWh+
Power output
~1,029 W+
Startup capability
~2,029 W
See calculation details
Device energy
4,650 Wh
After 85% conversion efficiency
5,471 Wh
After separate 15% reserve
6,437 Wh
RECOMMENDED MATCHES
How scoring works
No product in the current verified set meets the required energy, continuous-output, and surge-output thresholds.