Belt Length (L) is a function of shaft center distance and pulley diameters.

Most belts are made in standard lengths which are cheaper and easier to obtain than non-standard ones. Some (particularly plain flat belting) can be supplied in straight lengths which can be joined round the pulleys.

However, these are recommended only if the assembly of a continuous belt is difficult.

The nominal length calculated above should be modified to the nearest standard length, and the shaft centre distance amended to suit.

Manufacturers’ catalogues should be consulted to determine the standard lengths available for specific belt types.