RC Gear Ratio Calculator

This app is the best gearing tool for your RC car. Forget the slow web calculators with limited features. 

This application turns your iOS device into an invaluable tool for setting up and maintaining your RC cars.


-Make gearing calculations in seconds.

- Calculate FDR (final drive ratio) and Rollout.

- Save your favorite cars for quick access.

- Keep notes and gearing for all your cars.

- Access our database of 2000+ cars.

- Change the gear pitch.

-Smart alternative ratios in other pitches will be shown.


Proper gearing is one of the most essential tuning options required to maximize the performance of your car. The key to proper gearing is finding and maintaining the best rollout for each track environment, motor/chassis setup and driving style. Rollout is the distance a car will travel in one revolution of the motor shaft. Pinion and spur gears are used to generate the rollout desired, considering the diameter of the tires mounted. Rollout determines top speed and acceleration. Usually, a higher rollout will provide less acceleration and more top speed, and a lower rollout will be quicker off the line, but with less top speed.

All brands and trademarks appearing in the app are the property of their respective owners and are mentioned for descriptive and/or indicative purposes only.