How many watts is 1 horsepower?

One mechanical horsepower equals approximately 745.7 watts, while one metric horsepower (PS) equals approximately 735.5 watts. Horsepower is commonly used to rate engine and motor output.

What is the relationship between watts and joules?

1 watt = 1 joule per second. If a device uses 1,000 watts (1 kilowatt) for one hour, it consumes 3,600,000 joules (3.6 megajoules) of energy.

Power Converter

Convert power measurements between watts, horsepower, BTU per hour, and more.

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Complete List of Power Units for Conversion

1 Exawatt [EW] = 1.00000e+18 Watt [W]

Exawatt to Watt, Watt to Exawatt

1 Petawatt [PW] = 1.00000e+15 Watt [W]

Petawatt to Watt, Watt to Petawatt

1 Terawatt [TW] = 1.00000e+12 Watt [W]

Terawatt to Watt, Watt to Terawatt

1 Gigawatt [GW] = 1.00000e+9 Watt [W]

Gigawatt to Watt, Watt to Gigawatt

1 Megawatt [MW] = 1.00000e+6 Watt [W]

Megawatt to Watt, Watt to Megawatt

1 Kilowatt [kW] = 1000.00 Watt [W]

Kilowatt to Watt, Watt to Kilowatt

1 Hectowatt [hW] = 100.000 Watt [W]

Hectowatt to Watt, Watt to Hectowatt

1 Dekawatt [daW] = 10.0000 Watt [W]

Dekawatt to Watt, Watt to Dekawatt

1 Deciwatt [dW] = 0.100000 Watt [W]

Deciwatt to Watt, Watt to Deciwatt

1 Centiwatt [cW] = 0.0100000 Watt [W]

Centiwatt to Watt, Watt to Centiwatt

1 Milliwatt [mW] = 0.00100000 Watt [W]

Milliwatt to Watt, Watt to Milliwatt

1 Microwatt [µW] = 0.00000100000 Watt [W]

Microwatt to Watt, Watt to Microwatt

1 Nanowatt [nW] = 1.00000e-9 Watt [W]

Nanowatt to Watt, Watt to Nanowatt

1 Picowatt [pW] = 1.00000e-12 Watt [W]

Picowatt to Watt, Watt to Picowatt

1 Femtowatt [fW] = 1.00000e-15 Watt [W]

Femtowatt to Watt, Watt to Femtowatt

1 Attowatt [aW] = 1.00000e-18 Watt [W]

Attowatt to Watt, Watt to Attowatt

1 Exajoule per Second [EJ/s] = 1.00000e+18 Watt [W]

Exajoule per Second to Watt, Watt to Exajoule per Second

1 Petajoule per Second [PJ/s] = 1.00000e+15 Watt [W]

Petajoule per Second to Watt, Watt to Petajoule per Second

1 Terajoule per Second [TJ/s] = 1.00000e+12 Watt [W]

Terajoule per Second to Watt, Watt to Terajoule per Second

1 Gigajoule per Second [GJ/s] = 1.00000e+9 Watt [W]

Gigajoule per Second to Watt, Watt to Gigajoule per Second

1 Megajoule per Second [MJ/s] = 1.00000e+6 Watt [W]

Megajoule per Second to Watt, Watt to Megajoule per Second

1 Kilojoule per Second [kJ/s] = 1000.00 Watt [W]

Kilojoule per Second to Watt, Watt to Kilojoule per Second

1 Hectojoule per Second [hJ/s] = 100.000 Watt [W]

Hectojoule per Second to Watt, Watt to Hectojoule per Second

1 Dekajoule per Second [daJ/s] = 10.0000 Watt [W]

Dekajoule per Second to Watt, Watt to Dekajoule per Second

1 Decijoule per Second [dJ/s] = 0.100000 Watt [W]

Decijoule per Second to Watt, Watt to Decijoule per Second

1 Centijoule per Second [cJ/s] = 0.0100000 Watt [W]

Centijoule per Second to Watt, Watt to Centijoule per Second

1 Millijoule per Second [mJ/s] = 0.00100000 Watt [W]

Millijoule per Second to Watt, Watt to Millijoule per Second

1 Microjoule per Second [µJ/s] = 0.00000100000 Watt [W]

Microjoule per Second to Watt, Watt to Microjoule per Second

1 Nanojoule per Second [nJ/s] = 1.00000e-9 Watt [W]

Nanojoule per Second to Watt, Watt to Nanojoule per Second

1 Picojoule per Second [pJ/s] = 1.00000e-12 Watt [W]

Picojoule per Second to Watt, Watt to Picojoule per Second

1 Femtojoule per Second [fJ/s] = 1.00000e-15 Watt [W]

Femtojoule per Second to Watt, Watt to Femtojoule per Second

1 Attojoule per Second [aJ/s] = 1.00000e-18 Watt [W]

Attojoule per Second to Watt, Watt to Attojoule per Second

1 Joule per Second [J/s] = 1.00000 Watt [W]

Joule per Second to Watt, Watt to Joule per Second

1 Joule per Minute [J/min] = 0.0166667 Watt [W]

Joule per Minute to Watt, Watt to Joule per Minute

1 Joule per Hour [J/h] = 0.000277778 Watt [W]

Joule per Hour to Watt, Watt to Joule per Hour

1 Kilojoule per Hour [kJ/h] = 0.277778 Watt [W]

Kilojoule per Hour to Watt, Watt to Kilojoule per Hour

1 Kilojoule per Minute [kJ/min] = 16.6667 Watt [W]

Kilojoule per Minute to Watt, Watt to Kilojoule per Minute

1 Horsepower (Mechanical) [hp] = 745.700 Watt [W]

Horsepower (Mechanical) to Watt, Watt to Horsepower (Mechanical)

1 Horsepower (Metric) [PS] = 735.499 Watt [W]

Horsepower (Metric) to Watt, Watt to Horsepower (Metric)

1 Horsepower (Boiler) [hp (boiler)] = 9809.50 Watt [W]

Horsepower (Boiler) to Watt, Watt to Horsepower (Boiler)

1 Horsepower (Electric) [hp (electric)] = 746.000 Watt [W]

Horsepower (Electric) to Watt, Watt to Horsepower (Electric)

1 Horsepower (Water) [hp (water)] = 746.043 Watt [W]

Horsepower (Water) to Watt, Watt to Horsepower (Water)

1 Horsepower (UK) [hp (UK)] = 745.700 Watt [W]

Horsepower (UK) to Watt, Watt to Horsepower (UK)

1 Pferdestarke [ps] = 735.499 Watt [W]

Pferdestarke to Watt, Watt to Pferdestarke

1 Ton of Refrigeration [TR] = 3516.85 Watt [W]

Ton of Refrigeration to Watt, Watt to Ton of Refrigeration

1 BTU (IT) per Hour [BTU/h] = 0.293071 Watt [W]

BTU (IT) per Hour to Watt, Watt to BTU (IT) per Hour

1 BTU (IT) per Minute [BTU/min] = 17.5843 Watt [W]

BTU (IT) per Minute to Watt, Watt to BTU (IT) per Minute

1 BTU (IT) per Second [BTU/s] = 1055.06 Watt [W]

BTU (IT) per Second to Watt, Watt to BTU (IT) per Second

1 BTU (th) per Hour [BTU(th)/h] = 0.292875 Watt [W]

BTU (th) per Hour to Watt, Watt to BTU (th) per Hour

1 BTU (th) per Minute [BTU(th)/min] = 17.5725 Watt [W]

BTU (th) per Minute to Watt, Watt to BTU (th) per Minute

1 BTU (th) per Second [BTU(th)/s] = 1054.35 Watt [W]

BTU (th) per Second to Watt, Watt to BTU (th) per Second

1 MBTU (IT) per Hour [MBTU/h] = 293071 Watt [W]

MBTU (IT) per Hour to Watt, Watt to MBTU (IT) per Hour

1 MBH [MBH] = 293.071 Watt [W]

MBH to Watt, Watt to MBH

1 Kilocalorie (IT) per Hour [kcal/h] = 1.16300 Watt [W]

Kilocalorie (IT) per Hour to Watt, Watt to Kilocalorie (IT) per Hour

1 Kilocalorie (IT) per Minute [kcal/min] = 69.7800 Watt [W]

Kilocalorie (IT) per Minute to Watt, Watt to Kilocalorie (IT) per Minute

1 Kilocalorie (IT) per Second [kcal/s] = 4186.80 Watt [W]

Kilocalorie (IT) per Second to Watt, Watt to Kilocalorie (IT) per Second

1 Kilocalorie (th) per Hour [kcal(th)/h] = 1.16222 Watt [W]

Kilocalorie (th) per Hour to Watt, Watt to Kilocalorie (th) per Hour

1 Kilocalorie (th) per Minute [kcal(th)/min] = 69.7333 Watt [W]

Kilocalorie (th) per Minute to Watt, Watt to Kilocalorie (th) per Minute

1 Kilocalorie (th) per Second [kcal(th)/s] = 4184.00 Watt [W]

Kilocalorie (th) per Second to Watt, Watt to Kilocalorie (th) per Second

1 Calorie (IT) per Hour [cal/h] = 0.00116300 Watt [W]

Calorie (IT) per Hour to Watt, Watt to Calorie (IT) per Hour

1 Calorie (IT) per Minute [cal/min] = 0.0697800 Watt [W]

Calorie (IT) per Minute to Watt, Watt to Calorie (IT) per Minute

1 Calorie (IT) per Second [cal/s] = 4.18680 Watt [W]

Calorie (IT) per Second to Watt, Watt to Calorie (IT) per Second

1 Calorie (th) per Hour [cal(th)/h] = 0.00116222 Watt [W]

Calorie (th) per Hour to Watt, Watt to Calorie (th) per Hour

1 Calorie (th) per Minute [cal(th)/min] = 0.0697333 Watt [W]

Calorie (th) per Minute to Watt, Watt to Calorie (th) per Minute

1 Calorie (th) per Second [cal(th)/s] = 4.18400 Watt [W]

Calorie (th) per Second to Watt, Watt to Calorie (th) per Second

1 Foot-Pound Force per Hour [ft·lbf/h] = 0.000376616 Watt [W]

Foot-Pound Force per Hour to Watt, Watt to Foot-Pound Force per Hour

1 Foot-Pound Force per Minute [ft·lbf/min] = 0.0225970 Watt [W]

Foot-Pound Force per Minute to Watt, Watt to Foot-Pound Force per Minute

1 Foot-Pound Force per Second [ft·lbf/s] = 1.35582 Watt [W]

Foot-Pound Force per Second to Watt, Watt to Foot-Pound Force per Second

1 Pound-Foot per Hour [lbf·ft/h] = 0.000376616 Watt [W]

Pound-Foot per Hour to Watt, Watt to Pound-Foot per Hour

1 Pound-Foot per Minute [lbf·ft/min] = 0.0225970 Watt [W]

Pound-Foot per Minute to Watt, Watt to Pound-Foot per Minute

1 Pound-Foot per Second [lbf·ft/s] = 1.35582 Watt [W]

Pound-Foot per Second to Watt, Watt to Pound-Foot per Second

1 Erg per Second [erg/s] = 1.00000e-7 Watt [W]

Erg per Second to Watt, Watt to Erg per Second

1 Volt Ampere [VA] = 1.00000 Watt [W]

Volt Ampere to Watt, Watt to Volt Ampere

1 Kilovolt Ampere [kVA] = 1000.00 Watt [W]

Kilovolt Ampere to Watt, Watt to Kilovolt Ampere

1 Newton Meter per Second [N·m/s] = 1.00000 Watt [W]

Newton Meter per Second to Watt, Watt to Newton Meter per Second

Understanding power units

The watt (W) is the SI unit of power, representing energy transfer per unit time. One watt equals one joule per second. Power measures the rate at which work is done or energy is transferred.

Common power relationships

1 kilowatt (kW) = 1,000 watts
1 horsepower (hp) ≈ 745.7 watts
1 metric horsepower ≈ 735.5 watts
1 BTU per hour ≈ 0.293 watts
1 foot-pound per second ≈ 1.356 watts

Applications of power units

Watts and kilowatts are used for electrical appliances and power plants. Horsepower is used for engines and motors, particularly in automotive and mechanical applications. BTU per hour is used in HVAC and heating systems. Foot-pounds per second are used in some engineering contexts.

Frequently Asked Questions

How many watts is 1 horsepower?: One mechanical horsepower equals approximately 745.7 watts, while one metric horsepower (PS) equals approximately 735.5 watts. Horsepower is commonly used to rate engine and motor output.
What is the relationship between watts and joules?: 1 watt = 1 joule per second. If a device uses 1,000 watts (1 kilowatt) for one hour, it consumes 3,600,000 joules (3.6 megajoules) of energy.

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