Motor Power–Torque–Speed Calculator
Solve P = T·ω any direction with the 9550 rule — watts, newton-metres, RPM and horsepower, with the worked conversion.
9550 = 60000/2π — worth memorising: a 1.5 kW motor at 1440 RPM gives 9550×1.5/1440 ≈ 10 N·m. This is SHAFT (mechanical) power: electrical input is higher by the efficiency, and starting torque of induction motors is typically 1.5–3× rated.
Motor Power-Torque-Speed Calculator computes any one of power, torque and speed from the other two — free, instant and private in your browser. Anyone reading motor nameplates, sizing drives or converting hp ↔ kW ↔ N·m 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 Motor Power–Torque–Speed Calculator
Motor Power-Torque-Speed Calculator computes any one of power, torque and speed from the other two using the standard engineering relation: P = T·ω = T·2πn/60 — memorably, T(N·m) = 9550·P(kW)/n(RPM). Worked live: a 750 W motor at 2850 RPM produces 2.5 N·m at the shaft. 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 Motor Power–Torque–Speed Calculator
- 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 Motor Power–Torque–Speed Calculator?
- ✓Implements the real formula — P = T·ω = T·2πn/60 — memorably, T(N·m) = 9550·P(kW)/n(RPM) — with the substitution shown, not a black box
- ✓Built for anyone reading motor nameplates, sizing drives or converting hp ↔ kW ↔ N·m
- ✓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 motor power-torque-speed?+
Any one of power, torque and speed from the other two follows P = T·ω = T·2πn/60 — memorably, T(N·m) = 9550·P(kW)/n(RPM). For example, a 750 W motor at 2850 RPM produces 2.5 N·m at the shaft. The calculator applies the same relation and shows the substituted arithmetic so you can verify every step.
Where does the 9550 constant come from?+
Pure unit conversion: P = T·2πn/60 rearranged for T in N·m with P in kW and n in RPM gives T = P·60000/(2π·n) ≈ 9550·P/n. Worth memorising — it turns any nameplate into torque instantly.
Is nameplate power electrical or mechanical?+
Mechanical (shaft) output. Electrical input is higher by the efficiency — a 1.5 kW, 88 % motor draws ~1.7 kW. Heat dissipated is the difference, which matters for enclosure and supply sizing.
Is the Motor Power-Torque-Speed 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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