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Mechanical Engineering · Calculator

Gear Ratio Calculator

Calculate gear ratio, output speed and basic tooth-count relationship.

Enter your values

Use the units shown and enter valid values.

Enter a numeric value.
Enter a numeric value.
Enter a numeric value.
Enter a numeric value.

Calculation Result

Results are calculated from your inputs.

Enter your values and select Calculate to see the result.

How It Works

Calculate gear ratio, output speed and basic tooth-count relationship.

Gear Ratio = Input RPM ÷ Output RPM = Driven Teeth ÷ Driver Teeth

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: Input RPM; Output RPM; Driver gear teeth (optional check); Driven gear teeth (optional check). 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.