# Shaft Power Calculator

> Calculate shaft power step by step: P = 2π × N × T ÷ 60 (N in rpm, T in N·m, P in W).

Page: https://freecalculator.tech/tools/shaft-power-calculator
Last reviewed: 2026-11-03

## Formula

P = 2π × N × T ÷ 60 (N in rpm, T in N·m, P in W).

- 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.

## Inputs

- Torque
- Speed

## 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.

## Worked example: 200 N·m at 3,000 rpm

1. P = 2 x pi x 3,000 x 200 / 60 = 62,832 W
2. P = 62.83 kW, about 84.26 hp

## 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.

## 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.

## Sources

- OpenStax (Rice University) — https://openstax.org/details/books/university-physics-volume-1

## Cite this page

- APA: Free Calculator. (2026, November 3). Shaft Power Calculator. https://freecalculator.tech/tools/shaft-power-calculator
- MLA: "Shaft Power Calculator." Free Calculator, 3 Nov. 2026, https://freecalculator.tech/tools/shaft-power-calculator.
- Link: Shaft Power Calculator — Free Calculator, https://freecalculator.tech/tools/shaft-power-calculator