Gear Ratio Calculator (2-stage)
Ratio, output speed and output torque for one or two gear stages, with per-stage efficiency — teeth in, answers out.
Power is conserved (minus η): you trade speed for torque, never both. Prefer tooth counts with no common factor (e.g. 13:60, not 12:60) — a “hunting tooth” spreads wear evenly. Worm stages give big ratios in one step and self-lock above ~30:1, but the efficiency penalty turns into heat.
Gear Ratio Calculator computes ratio, output speed and output torque through one or two gear stages — free, instant and private in your browser. Robotics teams, gearbox repairers and students doing machine-design homework use it to skip the datasheet algebra: type your numbers, read the answer with the substituted formula shown step by step, and share an exact permalink of the calculation.
About Gear Ratio Calculator (2-stage)
Gear Ratio Calculator computes ratio, output speed and output torque through one or two gear stages using the standard engineering relation: i = Π(driven/driver teeth); n(out) = n(in)/i; T(out) = T(in)·i·η per stage. Worked live: 12→60 teeth is 5:1 — 1500 RPM in becomes 300 RPM out with ~4.75× torque at 95 % efficiency. The result recalculates on every keystroke, the worked-example panel shows your numbers substituted into the formula, and the Copy permalink button encodes the inputs in the URL so a colleague opens exactly your calculation. Everything runs client-side — nothing you type leaves your device.
How to use Gear Ratio Calculator (2-stage)
- 1Enter your values — the tool starts with realistic defaults for this exact use case, so the worked example is meaningful immediately.
- 2Read the live result and the worked-example panel, which substitutes your numbers into the formula step by step.
- 3Adjust any input to compare scenarios, then use Copy result or Copy permalink to share the calculation.
Why use Gear Ratio Calculator (2-stage)?
- ✓Implements the real formula — i = Π(driven/driver teeth) — with the substitution shown, not a black box
- ✓Built for robotics teams, gearbox repairers and students doing machine-design homework
- ✓Copy result and permalink buttons — share the exact calculation in a README, forum answer or design review
- ✓100% free, no sign-up, runs entirely in your browser (works offline once loaded)
Frequently asked questions
How do you calculate gear ratio?+
Ratio, output speed and output torque through one or two gear stages follows i = Π(driven/driver teeth); n(out) = n(in)/i; T(out) = T(in)·i·η per stage. For example, 12→60 teeth is 5:1 — 1500 RPM in becomes 300 RPM out with ~4.75× torque at 95 % efficiency. The calculator applies the same relation and shows the substituted arithmetic so you can verify every step.
Does gearing increase power?+
Never — power out = power in × efficiency. Gears trade speed for torque in exact proportion. If a calculation shows more output power than input, a number is wrong (usually the efficiency or a ratio inverted).
What's a hunting-tooth ratio and should I use one?+
Tooth counts with no common factor (13:60 instead of 12:60) make every tooth eventually mesh with every other, spreading wear evenly instead of developing repeating wear patterns. Costs nothing at design time — a free reliability upgrade.
Is the Gear Ratio Calculator free and private?+
Yes — completely free with no sign-up or usage limits, and it runs entirely in your browser: the values you enter are never uploaded or stored on a server.
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