Shaft Power ↔ Torque ↔ Speed Calculator
The P = 2πNT/60 triangle solved for torque.
9550 = 60×1000/2π — memorize it and you own every drive calculation. Same kW at half speed = double torque: why gearboxes exist and why low-rpm motors are big.
Formula
Shaft Power ↔ Torque ↔ Speed Calculator is a free power torque rpm 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 Shaft Power ↔ Torque ↔ Speed Calculator
The P = 2πNT/60 triangle solved for torque. The calculation implements T = 9550·P(kW)/N(rpm) (US: T = 5252·HP/N lbf·ft) (Rotational power fundamentals). 9550 = 60×1000/2π — memorize it and you own every drive calculation. Same kW at half speed = double torque: why gearboxes exist and why low-rpm motors are big.
How to use Shaft Power ↔ Torque ↔ Speed Calculator
- 1Enter Power in kW.
- 2Enter Speed in rpm.
- 3Read Torque instantly — no submit button needed.
- 4Need US units? Flip the SI/Imperial toggle and every field converts.
Why use Shaft Power ↔ Torque ↔ Speed Calculator?
- ✓Implements the standard formula — T = 9550·P(kW)/N(rpm) (US: T = 5252·HP/N lbf·ft)
- ✓Reference cited on-page: Rotational power fundamentals
- ✓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 Shaft Power ↔ Torque ↔ Speed Calculator use?+
It computes T = 9550·P(kW)/N(rpm) (US: T = 5252·HP/N lbf·ft), per Rotational power fundamentals. 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?+
9550 = 60×1000/2π — memorize it and you own every drive calculation. Same kW at half speed = double torque: why gearboxes exist and why low-rpm motors are big.
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 Shaft Power ↔ Torque ↔ Speed 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.
Related Engineering tools
Reynolds Number Calculator
Compute Re from density, velocity, pipe diameter and viscosity — with instant laminar/turbulent classification.
● LiveLaminar vs Turbulent Flow Classifier
Classify hydraulic-oil or process-fluid flow regime from kinematic viscosity, line velocity and tube bore.
● LiveBernoulli Equation Solver
Solve downstream pressure between two points from velocities, elevations and fluid density (ideal, lossless).
● Live