Guides

How to Estimate RC Battery Runtime

Turn capacity and measured average current into a realistic runtime figure — with a reserve.

October 30, 2026 6 min read RC Calculator Team

The formula

Ideal runtime (min) = Capacity (mAh) / (1000 × Average Current (A)) × 60. The Battery Runtime Calculator applies it for you.

Get a real average current

The estimate is only as good as the input. Log a normal run with a wattmeter or telemetry and average the draw — do not guess from the motor's peak rating.

Apply a usable fraction

Multiply the ideal by your reserve fraction (e.g. 0.8). That is your working estimate — not a universal rule, your pack and style decide it.

Calibrate and repeat

Compare the estimate with a real stopwatch run, adjust the average current, and the next estimate gets sharper.

Keep solving

Get your measured average current first

Battery Runtime Calculator Battery capacity explained