Conversions
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Torque To Horsepower Converter.
Convert torque to horsepower with explicit density, concentration, or unit-system inputs.
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Results update as you type.
Mechanical power is torque × angular speed. Enter torque in N·m and speed in revolutions per minute; 1 mechanical hp = 745.6998715822702 W.
FAQs
How does the torque to horsepower converter work?
Convert torque to horsepower with explicit density, concentration, or unit-system inputs.
Use Cases
Automotive Performance Tuning
Quickly estimate the horsepower output of an engine based on its torque and RPM, useful for comparing modifications or understanding performance curves.
Example: A car produces 300 lb-ft of torque at 4000 RPM. Horsepower = (300 × 4000) / 5252 ≈ 228 hp.
Electric Motor Sizing
Determine the mechanical horsepower of an electric motor from its torque and speed ratings, helping in equipment selection and power requirement analysis.
Example: A motor with 10 Nm torque at 1500 RPM: (10 × 1500) / 7127 ≈ 2.1 hp.
Frequently Asked Questions
- How do I use the Torque to Horsepower Converter?
- Enter the torque value (in lb-ft or Nm) and the rotational speed (in RPM) into the respective fields. The calculator will automatically compute the mechanical horsepower using the formula: Horsepower = (Torque × RPM) / 5252 (for lb-ft) or (Torque × RPM) / 7127 (for Nm).
- What units does this calculator support?
- The calculator supports torque in pound-feet (lb-ft) and Newton-meters (Nm), and rotational speed in revolutions per minute (RPM). It outputs mechanical horsepower (hp).
- Why is 5252 used in the formula?
- The constant 5252 comes from the relationship between horsepower, torque, and RPM. At 5252 RPM, torque and horsepower are equal in value when torque is measured in lb-ft. This is a standard conversion factor for mechanical horsepower.
Tips & Common Mistakes
Tips
- Ensure torque and RPM are measured at the same point in the engine's operating range for accurate results.
- If you have torque in Nm, use the constant 7127; if in lb-ft, use 5252. The calculator handles this automatically.
- For engines with variable torque, use peak torque and its corresponding RPM to get peak horsepower.
- Remember that this calculator provides an estimate; actual horsepower may vary due to drivetrain losses and other factors.
Common Mistakes to Avoid
- Using torque and RPM values from different engine speeds, which gives an inaccurate horsepower figure.
- Forgetting to convert torque units correctly, leading to incorrect results if you mix lb-ft and Nm without adjusting the formula.
- Assuming the calculated horsepower is the same as wheel horsepower, ignoring drivetrain losses.
Last updated: August 13, 2026