Pulley Sizes

To determine proper pulley size, use the calculator below.

The basic formula for this calculation is:

Pump RPM                 Motor Pulley

=

Motor RPM                 Pump  Pulley

You can achieve a more precise calculation, if required, by using the Pitch Diameter* of the pump and motor pulley.

To find the pitch diameter of the motor pulley use the following formula:

Pitch Diameter (Motor Pulley) = Pump RPM X Pitch Diameter of Pump Pulley
                                                                                 Motor RPM

To find the pitch diameter of the pump  pulley use the following formula:

Pitch Diameter (Pump Pulley) = Motor RPM X Pitch Diameter of Motor Pulley
                                                                           Pump  RPM

*When using “A” section belts, reduce the pulley size by 0.75”; this must be added back to the answer in the pulley size calculations.  When using “B” section belts, reduce the pulley size by 0.35”; this must be added back to the answer in the pulley size calculations.