RPM Calculator

Engine Speed Calculator

• Identify maximum vehicle speed in a given transmission gear

• Calculate ideal shift points in manual transmission vehicles

• Calculate cruising RPM at various vehicle speeds

• Identify changes in cruising RPM for corresponding tire size and axle ratio changes

Axle Ratio:

: 1

Transmission Ratio:

: 1

Tire Diameter:


Vehicle Speed:


Engine Speed: RPM


Note: This calculator does not take into consideration torque converter slippage, but will produce a reliable approximation of engine speed under constant conditions.