DynoCalc
Utility & Math

Battery Runtime Calculator

Estimate how long a battery, power bank, UPS, lantern, or medical-device battery can run a critical load.

Result

Estimated runtime is 6.4 hours.

Runtime

6.4 hr

Usable capacity

383 Wh

Device load

60 W

Reserve held back

10.00%

Learn the calculation

How it works

Emergency planning estimates use simple capacity, consumption, and timing formulas. Verify safety-critical decisions with official guidance, device manuals, and local emergency instructions.

Runtime = battery Wh x efficiency x (1 - reserve) / load watts

Example

Example battery runtime calculation

Use the default values in the calculator form. Press Calculate to see the result summary, supporting values, and formula.

FAQs

What does the Battery Runtime Calculator do?+

It turns your inputs into a clear battery runtime result and includes the formula used for the calculation.

Can I use this result for planning?+

Yes, it is useful for quick planning and comparison. For financial, health, legal, or tax decisions, confirm important numbers with a qualified professional.

Last updated: 2026-05-24

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