What is the formula for belt length?

For a 2-pulley system: L = 2·C + π·(D1+D2)/2 + (D1−D2)²/(4·C), where C is the center distance and D1, D2 are the pulley diameters. Three-pulley belts use the same wrap-plus-tangent approach, extended to three triangle sides.

Does center distance matter?

Yes. Center distance dominates belt length for any reasonable pulley-size difference. Treat it as the primary input; pulley diameters act as a correction term.

How precise is the calculation?

Math runs server-side in Python Decimal. Rounding is display-only — the underlying value is exact to many more decimals than any belt manufacturer's tolerance.

Belt Length Calculator

Calculate conveyor belt length, or find a missing value.

Pulley Configuration

Fill both pulley diameters, plus center distance or belt length.

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Pulley 2 Diameter

Center Distance

Belt Length

Result

Calculated Value

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