How many watts is one horsepower?

Mechanical horsepower is about 745.7 watts. Metric horsepower (PS, used in European car specs) is slightly less at 735.5 watts.

Why is AC measured in BTU/h?

Air conditioner and heating capacity is rated in BTU per hour — the rate at which it moves heat. A "12,000 BTU" unit is 12,000 BTU/h ≈ 3.5 kW of cooling.

What is the difference between power and energy?

Energy is the total amount (joules, kWh); power is the rate of using it (watts = joules per second). A 100 W bulb left on for 10 hours uses 1 kWh of energy.

Power Converter

Convert power units — watts, kilowatts, horsepower, and BTU per hour. For engines, appliances, and HVAC.

Converters

Watt W

Kilowatt kW

Megawatt MW

Horsepower (mech) hp

Horsepower (metric) PS

BTU per hour BTU/h

Foot-pound/sec ft·lb/s

About the power converter

Power is the rate of energy use — energy per unit time. Watts dominate in electronics and electricity, horsepower in engines, and BTU/h in heating and air conditioning. Note that "horsepower" has two slightly different definitions (mechanical and metric).

Conversion reference

1 W	=	1 W	Watt
1 W	=	0.001 kW	Kilowatt
1 W	=	1.0000e-6 MW	Megawatt
1 W	=	0.0013410221 hp	Horsepower (mech)
1 W	=	0.0013596216 PS	Horsepower (metric)
1 W	=	3.4121416 BTU/h	BTU per hour
1 W	=	0.73756215 ft·lb/s	Foot-pound/sec

All conversions run entirely in your browser — nothing is sent to a server. Factors are exact wherever an exact definition exists.