Pulley Speed Calculator (Belt Drive)
Driven speed from pulley diameters — the workshop's oldest calculation.
Keep V-belt speed in the 5–25 m/s sweet spot; past 30 m/s centrifugal tension eats grip. Real drives slip 1–2% — fan speeds always run slightly slow of this math.
Formula
Pulley Speed Calculator (Belt Drive) is a free pulley speed 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 Pulley Speed Calculator (Belt Drive)
Driven speed from pulley diameters — the workshop's oldest calculation. The calculation implements N₂ = N₁·D₁/D₂ (with 1–2% belt slip in practice) (V-belt drive design — manufacturer manuals). Keep V-belt speed in the 5–25 m/s sweet spot; past 30 m/s centrifugal tension eats grip. Real drives slip 1–2% — fan speeds always run slightly slow of this math.
How to use Pulley Speed Calculator (Belt Drive)
- 1Enter Motor (driver) speed in rpm.
- 2Enter Driver pulley Ø in mm.
- 3Enter Driven pulley Ø in mm.
- 4Read Driven speed, Belt velocity instantly — no submit button needed.
- 5Need US units? Flip the SI/Imperial toggle and every field converts.
Why use Pulley Speed Calculator (Belt Drive)?
- ✓Implements the standard formula — N₂ = N₁·D₁/D₂ (with 1–2% belt slip in practice)
- ✓Reference cited on-page: V-belt drive design — manufacturer manuals
- ✓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 Pulley Speed Calculator (Belt Drive) use?+
It computes N₂ = N₁·D₁/D₂ (with 1–2% belt slip in practice), per V-belt drive design — manufacturer manuals. 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?+
Keep V-belt speed in the 5–25 m/s sweet spot; past 30 m/s centrifugal tension eats grip. Real drives slip 1–2% — fan speeds always run slightly slow of this math.
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 Pulley Speed Calculator (Belt Drive) 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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