Shaft Power Calculator
Calculate shaft power step by step: P = 2π × N × T ÷ 60 (N in rpm, T in N·m, P in W).
In short
Calculate shaft power step by step: P = 2π × N × T ÷ 60 (N in rpm, T in N·m, P in W).
Formula: P = 2π × N × T ÷ 60 (N in rpm, T in N·m, P in W).
Shaft power
7.854 kW
- Watts
- 7,853.9816 W
- Horsepower
- 10.5324 hp
- Angular speed
- 157.0796 rad/s
Shaft power formula from torque and rpm
P (W) = 2 x pi x N x T / 60, where N is speed in rpm and T is torque in N·m. Angular speed in rad/s is 2 x pi x N / 60.
Power and torque formulas
| Find | Metric | Imperial |
|---|---|---|
| Power | P (W) = 2 x pi x N x T / 60 | hp = T (lb-ft) x rpm / 5,252 |
| Torque | T (N·m) = 60 x P / (2 x pi x N) | T (lb-ft) = hp x 5,252 / rpm |
| Units | 1 hp = 745.7 W | 1 lb-ft = 1.3558 N·m |
Torque from power
Rearrange the same formula: T = 60 x P / (2 x pi x N). In imperial units, hp = torque (lb-ft) x rpm / 5,252.
What this calculator does
Calculate shaft power step by step: P = 2π × N × T ÷ 60 (N in rpm, T in N·m, P in W). Worked example, questions and limitations included.
You enter torque and speed, and the shaft power calculator shows the answer along with the working, so you can check it or try other numbers.
The page shows the formula, a numeric worked example, and the assumptions that affect this mechanical calculation.
Inputs and what they mean
- Torque
- — number value.
- Speed
- — number value.
How to use it
- Enter each value in the unit shown next to the box (use the unit converter first if your numbers are in other units).
- Check the breakdown to see every intermediate step.
- Read the limitations before relying on the result.
Formula
Equivalent to P = T × ω, with ω = 2πN/60.
Speed cannot be negative.
Gives mechanical power at the shaft.
P = 2π × N × T ÷ 60 (N in rpm, T in N·m, P in W).
Inputs used: Torque, Speed.
Worked examples
Worked example: 200 N·m at 3,000 rpm
- P = 2 x pi x 3,000 x 200 / 60 = 62,832 W
- P = 62.83 kW, about 84.26 hp
Reading the result
The headline figure is the main answer. Any breakdown underneath shows the parts that make it up, so you can check the working and see what changes when you adjust an input.
Limitations and assumptions
- Steady torque and speed.
- Losses downstream not included.
- No shaft strength check.
- Results are estimates for planning and learning. Real designs, installations and bids must be checked by a qualified, licensed professional against the codes that apply where you work.
- The result depends on the values you enter for this shaft power calculator; it does not supply missing rates, rules, prices, dates, or assumptions for you.
Reference: OpenStax (Rice University)
Last reviewed:
Common questions
How do I find torque from power?
Rearrange: T = 60P ÷ (2πN).
Is this input or output power?
It is the mechanical power carried by the shaft at that torque and speed.
Can I use lb-ft and rpm?
Convert lb-ft to N·m (×1.3558) first, or use hp = T(lb-ft) × rpm ÷ 5,252.
How do I use the Shaft Power Calculator?
Enter the required values for Torque, Speed. The calculator applies the formula on this page and shows the main result with any supporting breakdown so you can check the arithmetic.
What formula does the Shaft Power Calculator use?
P = 2π × N × T ÷ 60 (N in rpm, T in N·m, P in W). The visible formula section above lists the calculation path and the edge cases the page handles, so the result can be checked without relying on the form alone.
Can the Shaft Power Calculator be used for exact decisions?
Use it as a calculation aid, not as a substitute for checking the underlying rule, contract, policy, or professional advice that applies to your situation. When a result depends on local rules, personal details, prices, or dates, enter those values yourself and confirm them before acting.
Sources
Method based on OpenStax (Rice University).
Cite this page
Free Calculator. (2026, November 3). Shaft Power Calculator. https://freecalculator.tech/tools/shaft-power-calculator
"Shaft Power Calculator." Free Calculator, 3 Nov. 2026, https://freecalculator.tech/tools/shaft-power-calculator.
Shaft Power Calculator — Free Calculator, https://freecalculator.tech/tools/shaft-power-calculator
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