Torque to Horsepower Calculator
Calculate horsepower and kilowatts from torque and RPM. Uses the standard formula: HP = (Torque × RPM) ÷ 5252.
Reviewed October 7, 2026 Runs in your browser — inputs are never stored
Power output
199.924 HP
kW
149.085
Metric HP (PS)
202.697
Torque (N·m)
406.746
This tool provides general unit conversions for everyday and educational use. For regulated, legal, or scientific applications, verify conversion factors against the applicable official standard.
About the Torque to Horsepower Calculator
The torque to horsepower calculator finds power from torque and engine speed. In US units, horsepower = torque (ft·lbf) × RPM ÷ 5,252; in metric units, kilowatts = torque (N·m) × RPM ÷ 9,549. That is why torque and horsepower curves always cross at 5,252 RPM when plotted in US units. It works for engines, electric motors and any rotating shaft.
How to use it
- 1Enter the torque and choose its unit.
- 2Enter the speed in RPM.
- 3Read the power in horsepower and kilowatts.
- 4Copy, share or print the result with the buttons below it.
Worked example
300 ft·lbf at 3,500 RPM gives 300 × 3,500 ÷ 5,252 ≈ 200 hp, or about 149 kW.
How it works
Formulas
HP = (ft·lbf × RPM) ÷ 5252
kW = (N·m × RPM) ÷ 9549
Where does 5252 come from?
5252 ≈ 33,000 ft·lbf/min ÷ (2π) — it combines the definition of 1 HP (33,000 ft·lbf/min) with the rotational-to-linear conversion factor.
Common use cases
- Reading engine dyno charts
- Sizing electric motors
- Comparing vehicle specifications
Frequently asked questions
A:They always cross at exactly 5252 RPM for US horsepower. At 5252 RPM, HP = ft·lbf numerically.
A:1 SAE HP = 550 ft·lbf/s = 745.7 W. 1 PS (Pferdestärke) = 735.499 W. They differ by about 1.4%.
Reviewed for accuracy · Last updated October 7, 2026
Conversion factors are based on internationally defined SI units and standard metric/imperial equivalence tables.
CalcWisee Editorial Team
Calculator development and formula review
CalcWisee is an independent site founded by Ayman. Every calculator is built from a published formula or official definition, tested against hand-worked examples before it goes live, and corrected promptly when a reader reports an issue to ayman@calcwisee.com.
Expertise: Financial mathematics, Health and fitness formulas, Applied mathematics, Unit conversion standards
References & sources
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