Calculate vehicle or machine speed based on engine RPM, gear ratios, and tire/wheel size.
Configuration
Calculation Results
Enter parameters to calculate speed
About this calculator
Overview
This calculator determines the linear speed (velocity) of a vehicle or rotating system by combining the rotational speed (RPM), total mechanical gear reduction (ratio), and the outer diameter of the driving wheel or tire.
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Pro Tips
Total Ratio includes Transmission gear ratio AND Final Drive (Differential) ratio.
Tire diameter is usually measured in inches or millimeters. Make sure to select the correct unit.
Higher gear ratios mean more torque but lower top speed for a given RPM.
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Fun Facts
"In top gear, 'overdrive' ratios are less than 1.0 (e.g., 0.85:1), allowing higher speeds at lower engine RPM for efficiency."
"Calculating tire diameter accurately is crucial; a tire's effective rolling radius is slightly smaller than its unloaded radius due to squash."
"Formula racing cars reach incredibly high speeds by combining high RPM engines (up to 15,000+) with specific gear ratios."
