Belt Length Calculator

GREYSUN ENGINEERING TOOL

Estimate open-belt length using the motor pulley diameter, driven pulley diameter, and center-to-center distance.

Motor Pulley Diameter

Driven Pulley Diameter

Center-to-Center Distance

Belt Profile

Estimated Belt Length

—

inches

Enter both pulley diameters and the center distance, then select Calculate.

Length in Inches —

Length in Millimeters —

Length in Feet —

Possible Belt Designation —

Select a belt profile to generate a possible catalog designation.

Formula Used

This calculator uses the standard approximate formula for an open-belt drive.

L = 2C + 1.5708(D + d) + (D − d)² ÷ 4C

Input Definitions

D is the larger pulley diameter, d is the smaller pulley diameter, and C is the center-to-center distance between shafts.

Unit Flexibility

Each measurement may be entered independently in inches or millimeters. The calculator automatically converts the values before calculating.

Important: This calculator estimates belt length and provides only a possible catalog designation. Belt numbering conventions differ by belt profile and manufacturer, and the listed length may represent inside, outside, datum, or pitch length. Horsepower, pulley groove, minimum pulley diameter, number of belts, belt construction, tensioning range, and service factor must also be checked. Always confirm the final belt number with the belt manufacturer or supplier before ordering or installing a belt.

Need Help With a Centrifuge Belt Drive?

Greysun can help evaluate pulley sizing, belt selection, alignment, vibration, drive speed, and centrifuge performance.

Talk to a Greysun Engineer