Pulley Ratio Calculator
Calculate pulley speed ratio and driven speed from pulley diameters.
Enter your values
Use the units shown and enter valid values.
Calculation Result
Results are calculated from your inputs.
How It Works
Calculate pulley speed ratio and driven speed from pulley diameters.
Use the result as an engineering calculation aid and verify critical designs against applicable standards and manufacturer specifications.
How to use this calculator
What to enter
Enter or select the following as requested: Driver pulley diameter; Driven pulley diameter; Driver RPM; Diameter unit. Follow the units, valid ranges, examples, and options displayed beside each field.
What the result means
The numerical result follows the operation or relationship named by the calculator and the values entered. Check the order of operations, sign, precision, and units shown, especially when combining percentages or ratios.
When to use it
Use this to calculate or verify a numerical value. Recheck the input values and rounding if the result will be used in a report, measurement, or further calculation.