Laptop Battery Life Calculator

Estimate laptop runtime from battery watt-hours, average power draw and usable battery percentage.

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Estimate laptop runtime from battery energy, average power draw and usable battery percentage.

TechnologyBatteryBrowser calculation

Result: Enter battery capacity and average power draw.

Formula used

Estimated hours = battery watt-hours × usable percentage ÷ average watts.

Runtime is only an estimate

Laptop power draw changes with brightness, CPU/GPU load, wireless use, peripherals, battery age and temperature. Manufacturer-rated capacity can also differ from usable energy.

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