Reference Tool
V-Belt Length Calculator
Enter the pitch diameter of both sheaves and the center distance between the shafts. We'll return the belt pitch length so you can match it to a standard A, B, C, D, 3V, 5V or 8V belt.
Inputs (inches)
Result
53.87 in
1368.2 mm
Round up to the nearest standard belt length. For classical V-belts add the section prefix (A, B, C) plus this length in inches — e.g. an 84-inch B-section belt is B84.
Quote this beltFormula & how it works
The pitch length of a two-sheave open V-belt drive is:L = 2C + π(D₁ + D₂) / 2 + (D₂ − D₁)² / 4Cwhere L is belt pitch length, C is center distance, and D₁ / D₂ are the sheave pitch diameters (not the OD).
Pitch diameter vs OD: the pitch diameter is where the belt actually rides — usually about 0.15" less than the OD on an A-section sheave, more on larger belts. Manufacturer catalogs list both. Use the pitch diameter for accurate belt length; use the OD only for clearance checks.
Common V-belt sections
| Section | Top width | Height | Typical HP range |
|---|---|---|---|
| A | 1/2" | 5/16" | 1 – 10 HP |
| B | 21/32" | 13/32" | 5 – 25 HP |
| C | 7/8" | 17/32" | 15 – 100 HP |
| D | 1-1/4" | 3/4" | 50 – 250 HP |
| 3V | 3/8" | 5/16" | 1 – 15 HP (narrow) |
| 5V | 5/8" | 17/32" | 10 – 100 HP (narrow) |
| 8V | 1" | 7/8" | 50 – 400 HP (narrow) |