Enter the motor speed (RPM) and the gear drive output speed (RPM) into the Sheave Ratio Calculator. The calculator will evaluate and display the Sheave Ratio.

## Sheave Ratio Formula

The following formula is used to calculate the Sheave Ratio.

SHR = MS / GS
• Where SHR is the Sheave Ratio
• MS is the motor speed (RPM)
• GS is the gear drive output speed (RPM)

To calculate the sheave ratio, divide the motor speed by the gear drive output speed.

## How to Calculate Sheave Ratio?

The following example problems outline how to calculate Sheave Ratio.

Example Problem #1:

1. First, determine the motor speed (RPM).
• The motor speed (RPM) is given as: 50.
2. Next, determine the gear drive output speed (RPM).
• The gear drive output speed (RPM) is provided as: 20.
3. Finally, calculate the Sheave Ratio using the equation above:

SHR = MS / GS

The values given above are inserted into the equation below and the solution is calculated:

SHR = 50 / 20 = 2.5

Example Problem #2:

For this problem, the variables required are provided below:

motor speed (RPM) = 60

gear drive output speed (RPM) = 10