Gear Module & Dimensions Calculator
All key gear dimensions from module and tooth count.
Measure a mystery gear: OD/(z+2) recovers the module. US diametral pitch DP = 25.4/module. Below 17 teeth (20° pressure angle) expect undercutting — use profile shift.
Formula
Gear Module & Dimensions Calculator is a free gear module for mechanical and machine-design engineers — instant, accurate and 100% client-side, with the governing formula and reference shown next to the result so the number can be defended, not just quoted.
About Gear Module & Dimensions Calculator
All key gear dimensions from module and tooth count. The calculation implements PCD = m·z; OD = m(z+2); root = m(z−2.5) (IS 4460; Maitra, Handbook of Gear Design). Measure a mystery gear: OD/(z+2) recovers the module. US diametral pitch DP = 25.4/module. Below 17 teeth (20° pressure angle) expect undercutting — use profile shift.
How to use Gear Module & Dimensions Calculator
- 1Enter Module in mm (Module = pitch Ø / teeth; bigger = beefier teeth).
- 2Enter Number of teeth.
- 3Read Pitch circle Ø, Outside Ø (addendum), Root Ø (dedendum) instantly — no submit button needed.
- 4Need US units? Flip the SI/Imperial toggle and every field converts.
Why use Gear Module & Dimensions Calculator?
- ✓Implements the standard formula — PCD = m·z; OD = m(z+2); root = m(z−2.5)
- ✓Reference cited on-page: IS 4460; Maitra, Handbook of Gear Design
- ✓One-click SI ⇄ Imperial toggle — values convert in place, physics stays in SI
- ✓Live worked example: the substitution recomputes from your numbers
- ✓Runs entirely in your browser — nothing uploaded, free forever
Frequently asked questions
What formula does the Gear Module & Dimensions Calculator use?+
It computes PCD = m·z; OD = m(z+2); root = m(z−2.5), per IS 4460; Maitra, Handbook of Gear Design. The formula is displayed under the result along with a worked example substituted with your own inputs.
What should I keep in mind when using this calculator?+
Measure a mystery gear: OD/(z+2) recovers the module. US diametral pitch DP = 25.4/module. Below 17 teeth (20° pressure angle) expect undercutting — use profile shift.
Is this suitable for machine design coursework?+
Yes — these are the exact Shigley/Machinery's-Handbook formulas, with the substitution shown step by step, so you can follow the worked example into your own calculation sheet.
Is the Gear Module & Dimensions Calculator free to use?+
Yes — completely free, no sign-up, no limits. It runs client-side in your browser, so inputs stay private and results are instant even on slow connections.
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