Belts & Pulleys
Belt Center Distance Calculator
Back-calculate the approximate shaft center distance for an open belt using belt length and pulley diameters.
Inputs
Formula
Inverse open-belt approximation
Worked example
Using the default values shown in the calculator, the same formula gives the following result. This is a quick sanity check for the calculation, not a design recommendation.
Inputs
- Belt length
- 1,500 mm
- Large pulley diameter
- 200 mm
- Small pulley diameter
- 100 mm
Result
- Estimated center distance
- 511.94 mm
Related calculators
Continue your workflow with a related calculation.
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Calculate approximate open-belt length from pulley diameters and center distance, with metric and imperial results.
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Calculate approximate belt wrap angle on the small and large pulleys of an open belt drive.
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Pulley Ratio Calculator
Calculate belt-drive speed ratio from driver and driven pulley diameters.
Frequently asked questions
Is this the inverse of the belt length calculator?
Yes. It algebraically solves the same common open-belt approximation for center distance.
Why might my installed center distance differ?
Standard belt lengths, tensioning travel, pulley geometry, and the belt manufacturer's length convention can change the final installation.