Horsepower From Torque Calculator
Convert torque and RPM to horsepower and kilowatts.
Enter your values
Choose one of: lb-ft, Nm.
Enter the torque you are working with.
Enter the engine speed in rpm.
Results update instantly as you type — no submit needed. Your values are remembered on this device, and the shareable link reopens the calculator with exactly these numbers.
- Horsepower
- 259.7 hp
- Kilowatts
- 193.7 kW
- Metric PS
- 263.3 PS
- Torque
- 310 lb-ft / 420.3 Nm
Quick answer
Horsepower = torque (lb-ft) × RPM ÷ 5252. The two curves always cross at 5,252 rpm because that is where the constant cancels.
hp = torque × rpm ÷ 5252
At a glance
| What it does | Convert torque and RPM to horsepower and kilowatts. |
|---|---|
| Category | Auto |
| Inputs needed | Torque unit, Torque, Engine speed |
| Main output | Horsepower |
| Formula | hp = torque × rpm ÷ 5252 |
| Cost | Free — no sign-up, no download |
How to use the Horsepower From Torque Calculator
- 1Pick whether your torque figure is in lb-ft or Nm.
- 2Enter the torque value and the RPM it was measured at.
- 3Read horsepower, kW and PS together.
Inputs explained
- Torque unit
- Choose one of: lb-ft, Nm.
- Torque
- Enter the torque you are working with.
- Engine speed(rpm)
- Enter the engine speed in rpm.
Worked example
Using the values the calculator loads with:
Inputs
- Torque unitlb-ft
- Torque310
- Engine speed4400 rpm
Results
- Horsepower259.7 hp
- Kilowatts193.7 kW
- Metric PS263.3 PS
- Torque310 lb-ft / 420.3 Nm
Frequently asked questions
Why do hp and torque cross at 5252 rpm?
Because horsepower = torque × rpm ÷ 5252, the two values are numerically equal exactly at 5,252 rpm on any engine.
Is kW or hp bigger?
One horsepower is about 0.746 kW, so a 200 hp engine is roughly 149 kW.
What do I need to enter into the Horsepower From Torque Calculator?
Just 3 values: torque unit, torque, engine speed. Every field starts with a realistic example, so you can change one number at a time and watch the result update instantly.
How does the Horsepower From Torque Calculator work out the answer?
Horsepower = torque (lb-ft) × RPM ÷ 5252. The two curves always cross at 5,252 rpm because that is where the constant cancels. It applies the formula hp = torque × rpm ÷ 5252 and shows the working so you can check each step by hand.
Is the Horsepower From Torque Calculator free, and do I need an account?
It is completely free with no sign-up, no download and no usage limit. Everything is calculated in your browser, so the numbers you type never leave your device.
Results are estimates for general information. For medical, legal, structural or financial decisions, confirm with a qualified professional.