Calculating the belt length and center distance

. Using the tooth pitch T, the two numbers of teeth of the pulleys Z1/Z2 and the center distance A, the theoretical effective length of the timing belt can be calculated as follows:
Formula for calculating the timing belt length

The specification of the tooth pitch is usually part of the product designation of the belt. The following table lists the tooth pitches of common timing belts.

Tooth pitches of different timing belts
T2.5 2.50 mm
T5 5.00 mm
T10 10.00 mm
GT2 2.00 mm
HTD-3M 3.00 mm
HTD-5M 5.00 mm
MXL 2.032mm
closed timing belt

In addition to belt lengths, timing belts are often characterized by the number of teeth.
Here, the number of teeth of the closed belt can be determined by the ratio between belt length and tooth pitch:

After selecting a standard belt length, the exact center distance can be calculated using the formula below:
Formula for calculating the center distance