Mechanical & Civil Engineering
Timing Belt Pitch, Tooth Count & Pulley Diameter Calculator
Compute pulley pitch diameter and required belt tooth count for a timing belt drive from belt pitch and tooth counts.
Your inputs
Change any value to update the result instantly.
Pulley pitch diameter
1.2732 in
Belt tooth count
150
Belt pitch
0.2 in
Pulley tooth count
20
What this calculator does
Timing Belt Pitch, Tooth Count & Pulley Diameter Calculator: Applies the standard machine-element relationship used in design textbooks so the capacity, rating or geometry can be worked out step by step.
What your result means
The headline figure is the capacity, rating or geometric result for the element you described. Compare it with the manufacturer's rating and your required service factor.
Formula and working
Dp = P·N / π; belt teeth = belt length / P
- 1
Collect the inputs
Belt pitch = 0.2 in; Pulley tooth count = 20; Total belt length = 30 in
- 2
Apply the formula
Dp = P·N / π; belt teeth = belt length / P
- 3
Result
Pulley pitch diameter = 1.2732 in
Frequently asked questions
Symbols and assumptions
- P
- Belt pitch (in)
- N
- Pulley tooth count
- beltLength
- Total belt length (in)
- • Standard textbook geometry and steady operating conditions are assumed; shock, misalignment and wear factors are not applied automatically.
- • Material and surface-finish allowances must be chosen by the user for their actual component.
Sources and review
Reviewed 2026-09-22 · Next review 2027-09-22
- • This is an educational estimate for learning and checking, not a design deliverable.
- • Real design must follow the governing code or standard for your jurisdiction and be reviewed and signed off by a qualified engineer.
- • Safety factors, load combinations and material certification are the responsibility of the designer, not of this page.
Important limitation
This is an educational estimate based only on the values and formula shown. Verify current rates, rules, units, and professional standards before relying on the result. It is not personalized financial or investment advice.
Report a mistake or request an improvement
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