RC Car Calculators

Work out how fast an RC car should run on paper, how spur and pinion choices change the final drive ratio, and how a different tire diameter or scale conversion affects the setup. Each calculator shows the formula it uses and the limits of the estimate.

Speed & Gearing

RC Car Speed

Theoretical top speed from motor KV, voltage, gearing and tire size.

KVVSpur TPinion TTire mm

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RC Gear Ratio

External and final drive ratio from spur, pinion and internal ratio.

Spur TPinion TInternal

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Tires & Setup

RC Tire Size

Speed change when you swap to a different tire diameter.

Open Calculator

Scale & Dimensions

RC Scale

Convert between full-size dimensions and model scale.

Open Calculator

Related guides and concepts