Horsepower (mechanical) to Watts Converter
Convert Horsepower (mechanical) (hp) to Watts (W) instantly, or use the conversion table below to look up common values.
Horsepower (mechanical) to Watts conversion table
| Horsepower (mechanical) (hp) | Watts (W) |
|---|---|
| 1 | 745.699872 |
| 2 | 1,491.399743 |
| 3 | 2,237.099615 |
| 4 | 2,982.799486 |
| 5 | 3,728.499358 |
| 10 | 7,456.998716 |
| 25 | 18,642.49679 |
| 50 | 37,284.993579 |
| 100 | 74,569.987158 |
How to convert Horsepower (mechanical) to Watts
1 hp equals 745.699872 W. Use the converter above for any value, or read the table for common conversions.
W = hp × 745.6998715822702 · hp = W × 0.0013410220895950279Multiply a horsepower (mechanical) figure by 745.699872 to get watts, or divide it by 0.001341 to go the other way.
Worked examples
- 1 hp= 745.699872 W
- 5 hp= 3,728.499358 W
- 10 hp= 7,456.998716 W
- 100 hp= 74,569.987158 W
- 500 hp= 372,849.935791 W
What these units are
Horsepower (mechanical) (hp). Mechanical horsepower is 745.7 watts, the unit used for engine and motor output in the United States and UK. It is a different size from metric horsepower.
Watts (W). The watt is the SI unit of power: one joule per second. It is used for light bulbs, small appliances and solar panel ratings; an LED bulb is typically 5 to 15 watts.
Metric power conversions are exact. Check whether a horsepower figure is mechanical or metric before comparing two engines.
Converting Horsepower (mechanical) to Watts in practice
Working in horsepower (mechanical)
Mechanical horsepower is exactly 745.7 watts, and metric horsepower is exactly 735.49875 watts. The two definitions differ by about 1.4 percent, so a figure carries a larger number in mechanical horsepower.
Vehicle engine output, pump and compressor motors, and agricultural machinery are commonly rated in horsepower. Metric horsepower is used for engine figures in much of Europe and Asia, while mechanical horsepower dominates in the United States.
Power is a rate, so multiplying horsepower by a running time gives an energy amount in joules or watt-hours. The gap of about 1.4 percent between the two horsepower definitions is carried through every conversion to watts.
Comparing two engine ratings without knowing which horsepower definition applies is the usual error, and the numbers are not interchangeable. The definition behind a figure should always be established before it is converted.
Horsepower is the unit for engine output, while kilowatts fit appliances, generators and inverters, and BTU per hour fits heating and cooling equipment. Metric horsepower is a separate sibling, so a PS figure and an hp figure differ even when they describe the same engine.
Reading the result in watts
The watt is the SI unit of power: one joule of energy transferred each second. Its symbol is W, and it is the base from which every larger power unit is built.
Watt ratings appear on light bulbs, televisions, kettles, solar panels, inverters and small generators. Physics and engineering use the watt for every rate of energy transfer, from a laser to a motor.
Because power is a rate and energy is an amount, a watt multiplied by a duration gives energy in joules or watt-hours. Metric steps above the watt are exact powers of one thousand.
A frequent error treats the watt as a quantity of energy, so an appliance rating is read as consumption. Power needs a time period before it becomes an amount of energy.
Watts suit appliance and electronics figures, kilowatts suit generators, inverters and solar arrays, and megawatts suit grid capacity. Milliwatts cover indicator lights and small sensors. Reading a generator rating in watts rather than kilowatts multiplies the number by a thousand and misstates the scale.
Checking a horsepower (mechanical) to watts conversion
Within the metric units a power conversion is a power of a thousand: watts to kilowatts, kilowatts to megawatts, and back. Those pairs are decimal shifts and a reader can do them without a converter.
Anything involving horsepower is a multiplication by a definition rather than a shift, and there are two definitions. Mechanical horsepower is exactly 745.7 watts and metric horsepower exactly 735.49875 watts, so the same engine carries a larger figure in mechanical horsepower than in metric.
When checking a power conversion, convert to watts first, because every unit in this dimension is defined against the watt and the intermediate value makes the comparison obvious. The trap is comparing a horsepower figure with a kilowatt figure without establishing which horsepower was quoted.
Tanzania reference points
Real quantities, converted into the units on this page.
Tanzania's installed electricity generation capacity
2,881.332 MW = 3,863,929.859457 hp = 2,881,332,000 W
EWURA reports 2,842.96 MW on the main grid and 38.372 MW off-grid, with TANESCO holding 92.31% of it. Installed capacity is what the country could generate at once, not what it generates on an average day.
Source: EWURA Fact Sheet — electricity sub-sector (installed capacity) · verified 2026-09-14
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