Power & Electrical Calculator
KW ↔ HP, Watts, Volts, Amps, Ohms — all conversions in one place
Fill any 2 fields — the other 2 will be calculated automatically.
Ohm's Law Formulas
P = V × I P = I² × R P = V² ÷ R
Energy & Cost Estimate
Common Appliance Wattage (India)
Torque & Speed Results
Formula
T = P × 9550 ÷ RPM (P in kW)
T = P × 7121 ÷ RPM (P in HP)
Quick Power Conversion Reference
| From | To kW | To HP | To Watts |
|---|---|---|---|
| 1 kW | 1 | 1.34102 | 1,000 |
| 1 HP (mech) | 0.74570 | 1 | 745.70 |
| 1 HP (metric) | 0.73550 | 0.98632 | 735.50 |
| 1 HP (elec) | 0.74600 | 1.00040 | 746.00 |
| 1 MW | 1,000 | 1,341.02 | 10,00,000 |
| 1 BTU/hr | 0.000293 | 0.000393 | 0.29307 |
Frequently Asked Questions
kW (kilowatt) is the SI unit of power. HP (horsepower) is an older unit still used for engines and motors. 1 kW = 1.341 HP (mechanical). Car engines in India are often rated in both — a 100 HP engine = 74.6 kW.
1 Unit = 1 kWh (kilowatt-hour). If a 1000W appliance runs for 1 hour, it uses 1 unit. In India, electricity costs Rs.5–10 per unit depending on state and slab.
Ohm's Law: V = I × R. Voltage (V) equals Current (I) multiplied by Resistance (R). Power P = V × I = I² × R = V²/R.
1 Mechanical HP = 745.7 Watts. 1 Electrical HP = 746 Watts. 1 Metric HP (PS) = 735.5 Watts. The difference is small but matters in precision engineering.
A 1.5 ton 5-star AC uses about 1.5 kW. Running 8 hours/day = 12 units/day. At Rs.8/unit = Rs.96/day, Rs.2,880/month. Use our Energy & Cost tab above for any appliance.