Horsepower to Torque Calculator
T (lb-ft) = 5252 × HP / RPM. The fundamental engine equation.
Result
Torque
315.1 lb-ft
427.2 N·m at 5000 RPM.
- HP300
- RPM5000
- Torque (lb-ft)315.12
- Torque (N·m)427.25
- Power (kW)223.71
Step-by-step
- T = 5252 × HP / RPM = 5252 × 300 / 5000 = 315.12 lb-ft.
- Convert: lb-ft × 1.356 = N·m.
- HP × 0.7457 = kW.
How to use this calculator
- Enter HP and RPM.
- Read torque in lb-ft and N·m.
About this calculator
Horsepower and torque are mathematically linked: HP = T × RPM / 5252 (or T = 5252 × HP / RPM). The constant 5252 comes from 33,000 ft-lb/min = 1 HP, divided by 2π (radians per revolution). At 5252 RPM, HP = T numerically — that's why dyno graphs cross at 5252 RPM. Diesels make peak torque low (1500-3000 RPM); racing engines peak high (7000-9000 RPM). Modern turbos: peak torque from 1500-5000 RPM (flat torque curve).
Frequently asked
33,000 ft-lb/min per HP / (2π) = 5252.11. Ensures HP = T × RPM / 5252.
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