Skip to content
Allin
Sign up · Sign in

Horsepower calculator

Compute engine horsepower from torque and RPM.

Related tools

All Performance tools →
Fiscal horsepower calculatorEstimate a car's fiscal horsepower (CV) — French formula.Gear ratio calculatorCompute the gear ratio from the number of teeth on the driving and driven gears.Flight Time CalculatorEstimate flight duration from route distance and cruise speed, with taxi/climb/descent overhead.Road trip time calculatorEstimate the total travel time of a road trip, including stops.EV charging time calculatorEstimate how long it takes to charge an electric vehicle between two battery levels.Car affordability calculatorFind a sensible monthly and yearly car budget from your income.Car depreciation calculatorEstimate a car's residual value after several years.Car lease calculatorEstimate a monthly car lease payment from price, down payment and residual value.

Enter Torque (Nm), Engine speed (RPM) and the Horsepower calculator works out Power (HP), Power (kW) straight away. For instance, with Torque (Nm) = 200 and Engine speed (RPM) = 5,000 it returns Power (HP) = 140.436 and Power (kW) = 104.723.

How to use it

  1. Enter your values: Torque (Nm), Engine speed (RPM).
  2. Read the result instantly: Power (HP), Power (kW).

Frequently asked questions

What does the Horsepower calculator actually compute?

It takes Torque (Nm) and Engine speed (RPM) and derives Power (HP) and Power (kW) from them. The calculation is live as you type, so the result updates on every change.

What information do I need to provide?

2 values: Torque (Nm) and Engine speed (RPM). Nothing else is required — no account, no file upload.

Can you show a worked example?

With Torque (Nm) = 200 and Engine speed (RPM) = 5,000, the calculator returns Power (HP) = 140.436 and Power (kW) = 104.723. Those figures come from running this exact tool, so you can reproduce them by entering the same values.

What happens if I enter larger values?

It moves a lot. Using Torque (Nm) = 400 and Engine speed (RPM) = 10,000 instead, Power (HP) goes from 140.436 to 561.743 — which is why it is worth testing a few scenarios rather than trusting a single figure.

What does it give for smaller values?

Scaled down to Torque (Nm) = 100 and Engine speed (RPM) = 2,500, Power (HP) comes out at 35.109. The relationship is worth checking at both ends before you rely on a single result.

When would I actually use this?

Reading a spec sheet: converting between units, comparing power-to-weight across two cars, and sanity-checking an acceleration claim.

What is the most common mistake?

Comparing horsepower figures from different standards. Metric PS, SAE and DIN horsepower differ by a few percent, and a kerb weight quoted without fluids and driver understates the real mass.

What is the difference between the Horsepower calculator and the Fiscal horsepower calculator?

This one returns Power (HP) and Power (kW); the Fiscal horsepower calculator returns Fiscal horsepower (CV). That is the whole difference — open the one whose figure you need.

Where do the figures come from, and how current are they?

Unit conversions are exact by definition. Acceleration estimates from power and weight ignore traction, gearing and aerodynamics, so they set a floor rather than a prediction.

Further reading

All guides →
ExplainerTorque vs Horsepower: What Each One Actually DoesTorque is the twisting force an engine makes; horsepower is how fast it does work. Learn the hp = torque × rpm ÷ 5252 link and why both numbers matter.ExplainerWhat Is Horsepower? Mechanical hp, Metric PS, and kWHorsepower measures the rate of doing work. Learn where the unit came from, how mechanical hp differs from metric PS/CV, and how both relate to kilowatts.ExplainerKnots to km/h: The Conversion and Where Knots Are UsedOne knot equals exactly 1.852 km/h and about 1.15 mph. See the exact conversion factor, why the nautical mile exists, and where aviation and shipping use knots.ExplainerEngine Displacement and Compression Ratio: What They Actually Tell YouBoth numbers are pure geometry — one is the volume a piston sweeps, the other a ratio of two volumes — and both are read as if they described power. Here is each derivation worked on real engines, and exactly what each number can and cannot support.ExplainerWhat Is Kinetic Energy? The KE = ½mv² Formula ExplainedKinetic energy is the energy of motion, given by KE = ½mv². Learn what the formula means, why speed matters most, and see worked examples in joules.ComparisonLeasing, Hire Purchase or Cash: the Five-Year Total, Not the Monthly PaymentThree ways to put the same car on the drive, priced over five years at the same interest rate. The monthly payments rank the options in exactly the reverse order of what they cost — and the gap turns out to be a single, computable number.