Motor Torque Calculator: Power to Torque Conversion
The Torque Calculator converts mechanical power to torque using speed and efficiency. Critical for pumps, fans, conveyors, and gearboxes.
Torque Formulas
T (Nm) = (P × 9550) / N (for kW)
T (lb-ft) = (P × 5252) / N (for HP)
Where:
- T = torque
- P = mechanical power output
- N = speed in RPM
P_mech = P_elec × η (η = efficiency)
Conversion Table (1 HP, 1750 RPM)
| Efficiency | Torque (Nm) | Torque (lb-ft) |
|---|---|---|
| 100% | 5.25 | 3.87 |
| 90% | 5.83 | 4.30 |
| 80% | 6.56 | 4.84 |
Breakdown Torque
Typically 200–300% of full-load torque. Use for starting heavy loads.
Applications
- Pumps: High torque at low speed
- Fans: Torque ∝ speed²
- Conveyors: Constant torque
Examples
- 10 HP, 1750 RPM, 92% eff → 40.1 lb-ft
- 7.5 kW, 1440 RPM, 88% eff → 46.3 Nm
Conclusion
Torque determines acceleration and load capacity. Use with Synchronous Speed and Slip tools.