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Belt drive calculators

Twenty calculators for V-belt, wedge-belt and timing-belt drives: from "what speed will this fan run at?" to a full drive design with tension and shaft load. Every result shows its formula, and every result can be sent to us for a quote with one tap.

Before you startDiameters are datum (pitch) diameters unless a box says "outside Ø". Results are engineering estimates using typical values for each belt section. For a final selection on a critical drive, confirm against the maker's power tables, or send us the result and we'll check it against the manufacturer's data.

Calculator pages

Each calculator also has its own page with a how-to and FAQ.

Belt length

Belt length calculator

Pulley speed

Pulley speed and size calculator

Belt tension

V-belt tension calculator

Drive design

V-belt drive design calculator

Timing belts

Timing belt calculator

Taper bush sizes

Taper lock bush sizes and torques

Fan & pump pulleys

Fan and pump pulley change calculator

Design a drive

Speed and power

Geometry

Tension and loads

Applications

Parts

Want the theory?Each calculator follows the method in the drive design guide; tensioning is explained in installation & tensioning.