Battery Life Calculator
Result
Battery Life Calculator Estimate how long a battery will last between charges. Enter the battery capacity in mAh and pick how heavily you use the device, and the calculator divides the capacity by an estimated drain rate to show the approximate runtime in — free online calculator.
Formula
- Battery Life Calculator calculates its result from Battery Capacity Mah, Drain Rate Ma Hr. It uses the formula Runtime (hours) = Battery Capacity (mAh) ÷ Drain Rate (mA/hr). Change any input to recalculate the result instantly.
- The main inputs are Battery Capacity Mah, Drain Rate Ma Hr. Enter them in the units and format shown in the calculator.
- Use the units, labels and assumptions shown beside each input so the formula is applied consistently.
- Changing any input above recalculates the result with the same calculation engine used by this page.
Example: Battery Life
- Battery Capacity Mah: 2
- Drain Rate Ma Hr: 5
Using Battery Capacity Mah = 2, Drain Rate Ma Hr = 5, the calculated result is 0.4.
Sample result: Calculating…
Frequently asked questions
What does the Battery Life calculate?
Battery Life Calculator Estimate how long a battery will last between charges. Enter the battery capacity in mAh and pick how heavily you use the device, and the calculator divides the capacity by an estimated drain rate to show the approximate runtime in — free online calculator.
Which values should I enter?
Enter Battery Capacity Mah, Drain Rate Ma Hr using the units and format shown beside each field.
What formula does this calculator use?
The calculator uses the following relationship: Runtime (hours) = Battery Capacity (mAh) ÷ Drain Rate (mA/hr).
Why might my result differ from another source?
Results can differ when another source uses different units, rounding rules, conventions or assumptions. Compare the inputs and definitions before comparing results.
Does the result update automatically?
Yes. Changing an input updates the result using the same calculation engine shown on this page.