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Convert Horsepower to Metric horsepower

1 horsepower is 1.01387 PS. One horsepower is exactly 1.01386966542 metric horsepower.

One horsepower is 1.0138697 metric horsepower. To convert horsepower to metric horsepower, multiply by 1.0138697; to go the other way, divide by 1.0138697 or multiply by 0.98632007. The factor is exact rather than rounded: it follows from NIST Special Publication 811. Mechanical horsepower: exactly 550 foot-pounds of work every second, the figure James Watt settled on to sell engines against pit ponies.

Factor checked against the defining standard · How we check

Metric horsepower
1.01387 PS
Horsepower × 1.0138697
value * 1.013869665421.014 PS

1 horsepower in every power unit

UnitValueExact factor
horsepower (as entered)1 hp
metric horsepower1.013869665 PS× 1.01386966542
watts745.6998716 W× 745.699871582
kilowatts0.7456998716 kW× 0.745699871582
megawatts0.0007456998716 MW× 0.000745699871582
BTU per hour2,544.433578 BTU/h× 2,544.43357764

Factors are entered by hand from NIST Special Publication 811 rather than derived from a units library, so the ones that terminate are exact rather than rounded.

How do you convert horsepower to metric horsepower?

  1. 1.Take the measurement in horsepower.
  2. 2.Multiply by 1.0138697 — that is how many metric horsepower fit in one horsepower.
  3. 3.To go back the other way, divide by 1.0138697, or multiply by 0.98632007.

Worked example: 25 horsepower to metric horsepower

Formula
hp × 1.0138697 = PS
Arithmetic
25 × 1.0138697 = 25.346742 PS
Answer
25 hp = 25.346742 PS

The factor is rounded for display; the figure above is computed from the full value.

Horsepower to metric horsepower conversion table

HorsepowerMetric horsepower
1 hp1.01387 PS
2 hp2.027739 PS
3 hp3.041609 PS
4 hp4.055479 PS
5 hp5.069348 PS
6 hp6.083218 PS
7 hp7.097088 PS
8 hp8.110957 PS
9 hp9.124827 PS
10 hp10.138697 PS
12 hp12.166436 PS
15 hp15.208045 PS
20 hp20.277393 PS
25 hp25.346742 PS
50 hp50.693483 PS
100 hp101.386967 PS
200 hp202.773933 PS
300 hp304.1609 PS
500 hp506.934833 PS
1000 hp1,013.869665 PS
2000 hp2,027.739331 PS
5000 hp5,069.348327 PS
10000 hp10,138.696654 PS

What is a horsepower?

Mechanical horsepower: exactly 550 foot-pounds of work every second, the figure James Watt settled on to sell engines against pit ponies. US vehicle and motor ratings use it.

What is a metric horsepower?

Exactly 75 kilogram-force metres a second, which is 1.4% less than mechanical horsepower. A German car quoted at 150 PS is 148 hp, and the difference is the definition rather than the engine.

How many metric horsepower are in a horsepower?

One horsepower is 1.0138697 metric horsepower. Going the other way, one metric horsepower is 0.98632007 horsepower. Both figures come from the same defined relation rather than from a measurement, which is why they are the same today as they were in 1959.

Every power unit here

UnitSymbolOne of these is
Horsepowerhp745.69987 watt
Metric horsepowerPS735.49875 watt
WattsWthe base unit
KilowattskW1000 watt
MegawattsMW1000000 watt
BTU per hourBTU/h0.29307107 watt

Source: NIST Special Publication 811 — mechanical horsepower is 550 ft·lbf/s exactly

Questions people actually ask

How many metric horsepower are in a horsepower?
1.0138697. Exactly 75 kilogram-force metres a second, which is 1.4% less than mechanical horsepower. A German car quoted at 150 PS is 148 hp, and the difference is the definition rather than the engine.
How do I convert metric horsepower back to horsepower?
Divide by 1.0138697, or multiply by 0.98632007 — they are the same operation.

Other power conversions

Metric horsepower to horsepower — the same conversion the other way.