Marks Calc
8 units

Power Converter

Convert between watts, kilowatts, megawatts, horsepower (mechanical and metric) and BTU/h.

Common power conversions

FromEquivalent
1 W1000 mW · 0.001 kW · 1.0000e-6 MW · 1.0000e-9 GW · 0.001341 hp
5 W5000 mW · 0.005 kW · 5.0000e-6 MW · 5.0000e-9 GW · 0.006705 hp
10 W10000 mW · 0.01 kW · 1.0000e-5 MW · 1.0000e-8 GW · 0.01341 hp
100 W100000 mW · 0.1 kW · 0.0001 MW · 1.0000e-7 GW · 0.134102 hp
1000 W1000000 mW · 1 kW · 0.001 MW · 1.0000e-6 GW · 1.341022 hp

How the conversion works

Linear: 1 hp (mech) ≈ 745.7 W, 1 hp (metric/PS) ≈ 735.5 W, 1 BTU/h ≈ 0.293 W.

When you'll use this converter

  • Car engines (hp ↔ kW)
  • Electrical appliances (W, kW)
  • Air conditioning (BTU/h ↔ kW)
  • Renewable energy (MW, GW)

Frequently asked

How many watts in 1 horsepower?

Mechanical: 1 hp ≈ 745.7 W. Metric: 1 hp (PS) ≈ 735.5 W. The mechanical definition is standard in the US/UK; metric is used in continental Europe.

How do I convert AC BTU/h to kW?

Divide BTU/h by 3,412 (or multiply by 0.000293). A 12,000 BTU/h AC ≈ 3.52 kW of cooling power.