Horsepower to Watts Converter

Convert HP to W with precision – Supports mechanical, electrical, and metric horsepower

Horsepower (HP)

Watts (W)

Quick Conversions

Conversion Formulas

Mechanical / Hydraulic Horsepower

One mechanical horsepower equals 745.699872 watts.

1 HP (mechanical) = 745.699872 W

Watts = HP × 745.699872

Example: 10 HP × 745.699872 = 7,456.99872 W

Electrical Horsepower

One electrical horsepower equals 746 watts.

1 HP (electrical) = 746 W

Watts = HP × 746

Example: 10 HP × 746 = 7,460 W

Metric Horsepower (PS)

One metric horsepower equals 735.49875 watts.

1 HP (metric) = 735.49875 W

Watts = HP × 735.49875

Example: 10 HP × 735.49875 = 7,354.9875 W

HP to Watts Conversion Table

Horsepower (HP)	Mechanical (W)	Electrical (W)	Metric (W)
0.25 HP	186.42 W	186.50 W	183.87 W
0.5 HP	372.85 W	373.00 W	367.75 W
0.75 HP	559.27 W	559.50 W	551.62 W
1 HP	745.70 W	746.00 W	735.50 W
2 HP	1,491.40 W	1,492.00 W	1,471.00 W
3 HP	2,237.10 W	2,238.00 W	2,206.50 W
5 HP	3,728.50 W	3,730.00 W	3,677.49 W
7.5 HP	5,592.75 W	5,595.00 W	5,516.24 W
10 HP	7,457.00 W	7,460.00 W	7,354.99 W
15 HP	11,185.50 W	11,190.00 W	11,032.48 W
20 HP	14,914.00 W	14,920.00 W	14,709.98 W
25 HP	18,642.50 W	18,650.00 W	18,387.47 W
50 HP	37,285.00 W	37,300.00 W	36,774.94 W
75 HP	55,927.49 W	55,950.00 W	55,162.41 W
100 HP	74,569.99 W	74,600.00 W	73,549.88 W
150 HP	111,854.98 W	111,900.00 W	110,324.81 W
200 HP	149,139.97 W	149,200.00 W	147,099.75 W
250 HP	186,424.97 W	186,500.00 W	183,874.69 W
500 HP	372,849.94 W	373,000.00 W	367,749.38 W
1000 HP	745,699.87 W	746,000.00 W	735,498.75 W

Conversion Examples

Car Engine: 150 HP to Watts

Input: 150 mechanical horsepower

Formula: 150 × 745.699872

Result: 111,854.98 W or 111.85 kW

Electric Motor: 5 HP to Watts

Input: 5 electrical horsepower

Formula: 5 × 746

Result: 3,730 W or 3.73 kW

Motorcycle: 75 HP to Watts

Input: 75 mechanical horsepower

Formula: 75 × 745.699872

Result: 55,927.49 W or 55.93 kW

Tractor: 200 HP to Watts

Input: 200 mechanical horsepower

Formula: 200 × 745.699872

Result: 149,139.97 W or 149.14 kW

Popular HP to Watts Conversions

Application	Typical HP	Watts (Mechanical)	Kilowatts (kW)
Household Fan	0.25 HP	186.42 W	0.19 kW
Sewing Machine	0.5 HP	372.85 W	0.37 kW
Garage Door Opener	0.75 HP	559.27 W	0.56 kW
Lawn Mower	3-5 HP	2,237-3,728 W	2.24-3.73 kW
Compact Car	100-150 HP	74,570-111,855 W	74.57-111.85 kW
Sedan	150-200 HP	111,855-149,140 W	111.85-149.14 kW
SUV	200-300 HP	149,140-223,710 W	149.14-223.71 kW
Sports Car	400-500 HP	298,280-372,850 W	298.28-372.85 kW
Motorcycle	50-100 HP	37,285-74,570 W	37.29-74.57 kW
Boat Engine	100-250 HP	74,570-186,425 W	74.57-186.42 kW
Industrial Motor	50-200 HP	37,285-149,140 W	37.29-149.14 kW
Generator	10-50 HP	7,457-37,285 W	7.46-37.29 kW

What is Horsepower?

Horsepower (HP) is a unit of measurement that quantifies power, specifically the rate at which work is performed. Originally developed by engineer James Watt in the late 18th century, horsepower was created to compare the output of steam engines with the power of draft horses.

      Key Fact: James Watt determined that a horse could turn a mill wheel 144 times in an hour, moving 180 pounds in a circle of 12-foot radius, which equals approximately 32,572 foot-pounds per minute. He rounded this to 33,000 foot-pounds per minute to define one horsepower.
    

Today, horsepower is commonly used in automotive, mechanical, and electrical engineering to describe engine performance, motor capacity, and power output. Different types of horsepower exist, including mechanical horsepower (745.699872 W), electrical horsepower (746 W), and metric horsepower (735.49875 W), each with slightly different values.

What is a Watt?

The watt (W) is the International System of Units (SI) standard unit for measuring power. Named after James Watt, one watt represents the rate of energy transfer equivalent to one joule per second. It quantifies how quickly energy is consumed or produced.

In practical applications, watts measure electrical power consumption in appliances, light bulbs, and electronic devices. Larger values are expressed in kilowatts (kW = 1,000 watts), megawatts (MW = 1,000,000 watts), or gigawatts (GW = 1,000,000,000 watts). For instance, a typical household light bulb might use 60 watts, while a car engine produces 75-150 kilowatts.

      Power Formula: Power (watts) = Energy (joules) ÷ Time (seconds). This relationship shows that watts measure the rate of energy consumption or production per unit of time.
    

HP to Watts: Differences Between Types

Type	Value in Watts	Common Use	Region
Mechanical HP	745.699872 W	Automotive engines, industrial motors, hydraulic systems	USA, UK
Electrical HP	746 W	Electric motors, generators, electrical equipment	USA
Metric HP (PS)	735.49875 W	European automotive specifications, machinery	Europe, Asia

The mechanical horsepower is most widely used in the United States for measuring engine power. The metric horsepower, also known as PS (Pferdestärke in German) or CV (chevaux-vapeur in French), is standard in European automotive specifications. Electrical horsepower is primarily used for electric motor ratings.

Related Power Conversions

Frequently Asked Questions

How many watts are in 1 horsepower?

One mechanical horsepower equals 745.699872 watts, one electrical horsepower equals 746 watts, and one metric horsepower equals 735.49875 watts. The mechanical horsepower is most commonly used in automotive and industrial applications.

Why are there different types of horsepower?

Different types of horsepower developed in various regions and industries. Mechanical horsepower originated in the USA for steam engines, electrical horsepower was standardized for electric motors, and metric horsepower was adopted in Europe. Each has a slightly different watt equivalent based on historical measurement standards.

What’s the difference between HP and kW?

Horsepower (HP) and kilowatts (kW) both measure power but use different scales. 1 HP equals approximately 0.746 kW, while 1 kW equals approximately 1.341 HP. Kilowatts are part of the metric system and are more commonly used internationally, while horsepower remains popular in the United States for automotive specifications.

How do I convert 100 HP to watts?

To convert 100 mechanical horsepower to watts, multiply by 745.699872: 100 × 745.699872 = 74,569.9872 watts, or approximately 74.57 kilowatts. For electrical HP, multiply by 746, resulting in 74,600 watts or 74.6 kW.

Which horsepower type should I use for my car?

In the United States, automotive manufacturers typically use mechanical horsepower (745.699872 W). European specifications often use metric horsepower or PS (735.49875 W). Check your vehicle’s documentation to determine which standard applies. Modern specifications increasingly include both HP and kW ratings.

Can I use this converter for electric motors?

Yes, this converter handles all types of horsepower, including electrical HP. Electric motors are often rated in electrical horsepower (746 W) or directly in kilowatts. Select “Electrical HP” from the dropdown menu for the most accurate conversion of electric motor specifications.

Is horsepower the same as torque?

No, horsepower and torque measure different aspects of engine performance. Torque measures rotational force (pound-feet or newton-meters), while horsepower measures power or work rate. They’re related by the formula: Horsepower = (Torque × RPM) ÷ 5,252. An engine can have high torque but low horsepower at low RPMs, or vice versa.

What’s the origin of the horsepower unit?

James Watt coined the term “horsepower” in the 1780s to market his steam engines. He observed draft horses working in mills and calculated that one horse could perform 33,000 foot-pounds of work per minute. This became the standard for comparing engine power to animal power, making it easier for customers to comprehend steam engine capabilities.