Horsepower Calculator
Convert between horsepower, kW, watts, torque, and RPM. Supports mechanical/electrical HP, single- and three-phase, plus quick HP↔kW conversions.
torque to hp calculator
Power can also be found from torque and speed: HP = 5252 / (T(lb·ft) × RPM) or in metric terms power, kW (T(N·m) × RPM) / 9550; kW / 0.746 = HP. Power factor and Efficiency should be included for motors.
Formula & Table Summary:
- HP = kW ÷ 0.746; kW = 0.746 × HP
- kW = (TN·m × RPM) ÷ 9550
- HP = (Tlb·ft × RPM) ÷ 5252
- 1φ: Pin(kW) = V × I × PF ÷ 1000
- 3φ: Pin(kW) = √3 × V × I × PF ÷ 1000
- Pout = η × Pin
Inputs: torque & RPM or kW/HP; optional V, I, PF, phase, η (motors). Outputs: kW, HP, and notes for sanity checks.
mechanical horsepower tool
Being a horsepower calculator, it converts power between horsepower (hp), kilowatts (kW), and watts (W) and calculates the HP given the torque and speed. Torque values can be entered in Nm or lb ft to give mechanical power, or values of kW or HP to quickly convert two ways (1 hp = 0.746 kW). Electrical input/output can be estimated using voltage, current, power factor, and either single-phase or three-phase motor efficiency. The tool offers the following standard variations: mechanical horsepower (imperial), metric power (kW), and water horsepower in hydraulic applications. Use it to size motors, verify nameplate ratings, compare alternatives, and reality-check field measurements. A concise/compact formula/table and sample table aid students, electricians, and engineers to verify results visually. Created to load quickly and to rank on low-competitive, calculator-based searches and remain accurate and practical.
electrical horsepower
| Case | Input | kW | HP |
|---|---|---|---|
| 1 | T=40 N·m, RPM=1500 | 6.28 | 8.42 |
| 2 | T=120 N·m, RPM=1800 | 22.62 | 30.33 |
| 3 | 10 kW (given) | 10.00 | 13.41 |
| 4 | 3φ: 415V, 20A, PF=0.85, η=0.90 | 11.00 | 14.76 |
Frequently Asked Questions - Horsepower Calculator:
How do I convert kW to horsepower?
Divide kW by 0.746 to get HP.
How do I get HP from torque and RPM?
HP = T(lb·ft)×RPM/5252 or kW = T(N·m)×RPM/9550, then HP = kW/0.746.
What is mechanical vs electrical horsepower?
Mechanical HP is shaft power; electrical HP is based on electrical input/output including PF and efficiency.
Is 1 HP exactly 746 W?
1 hp is defined as 745.7 W; calculators typically use 0.746 kW for simplicity.
How do I include efficiency?
Multiply electrical input kW by efficiency to estimate shaft output kW before converting to HP.
How do I convert watts to HP?
HP = W / 745.7.
Can I use N·m for torque?
Yes—use kW = T(N·m)×RPM/9550, then convert to HP.
What is water horsepower?
Water HP = (Flow×Head×γ)/(746×η); it estimates hydraulic shaft power at pumps/turbines.
Why does PF matter for motors?
PF affects input kW from V and I; lower PF raises current for the same real power.
What RPM gives 1 HP at 10 lb·ft?
RPM ≈ 5252×HP/T = 5252×1/10 ≈ 525 RPM.
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