How this home battery runtime calculator works
Usable battery energy is rated kWh × usable percentage. Runtime hours equals usable kWh ÷ load kW.
How to use it
- Battery capacity. Enter the value in kWh.
- Usable capacity. Enter the value in %.
- Average load. Enter the value in W.
- Request the result. Add your email, then select “Email & show my result.”
What to do with the number
Real loads change minute to minute, and inverter efficiency plus surge loads can reduce runtime. Estimate the average wattage of the circuits you actually plan to back up rather than using whole-home peak demand.
Planning estimate
Use this result as a starting point, not a guarantee. Product specifications, site conditions, manufacturer guidance, local codes, taxes, labor, tolerances, and rounding can change the real requirement or cost.