RPM to Speed Calculator

Use tire diameter, transmission ratio, and final-drive ratio for a no-slip gearing estimate.

Mode

Engine RPM

Tire diameter (in)

Transmission gear ratio

Final-drive ratio

—Speed mph

—Speed km/h

—Engine RPM

—Wheel RPM

—No-slip gearing estimate. Automatic-transmission converter slip, clutch slip, tire growth/deflection, and real rolling radius can change actual values.

How to use this RPM to Speed Calculator

Convert engine RPM and gearing into theoretical vehicle speed, or speed back into engine RPM. Enter your values above and the result is calculated directly in your browser. No account is required.

Fast answer, clear inputs

This tool is built around one job: give the answer quickly without forcing a signup or hiding the result. Related tools are linked nearby when the next calculation or conversion is useful.