What is the correct belt tension?

It varies by belt type. Press the middle span — 1-1.5cm deflection is normal. Over-tightening accelerates bearing wear.

Belt Length Calculator

ISO 4184

Pulley diameter + center distance → belt length + standard size matching. Supports V-belts and serpentine belts.

Input Parameters

INPUT PARAMETERS

Belt Type

Center Distance (inches)

12.0

260 in

Small Pulley Dia (inches)

4.0

124 in

Large Pulley Dia (inches)

6.0

136 in

Calculation Result

V-Belt · inch

Deviation -0.52%

Theoretical Length

39.8in

Formula calculation

Recommended Standard

40in

Recommended Size

Belt TypeV-Belt

Small Pulley Dia (D1)4 in

Large Pulley Dia (D2)6 in

Center Distance (C)12 in

Drive Ratio (D2/D1)1.50:1

Theoretical Length39.79 in

Recommended Standard40 in

Deviation-0.52%

Standard V-Belt Size Table

74 sizes (inches)

101112131415161718192021222324252627283031323334353637383940414243444546474850515253545556575860626364656668707275788084859096100105110120128132136140144158162

Theoretical length needs adjustment based on pulley groove profile and tension. Measure or consult your supplier for actual selection.

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