Horsepower to Milliwatts Conversion (hp to mW)

How to Convert Horsepower to Milliwatts

To convert horsepower to a milliwatt measurement, use one of the formulas below.

Mechanical Horsepower to Milliwatts

Formula to convert mechanical horsepower to milliwatts:

milliwatts = hp(I) × 745,699.871582

Since one mechanical horsepower is equal to 745,699.871582 milliwatts, the formula to find milliwatts is to multiply mechanical horsepower by 745,699.871582.

For example, here's how to convert 5 mechanical horsepower to milliwatts using the formula.

5 hp(I) = (5 × 745,699.871582) = 3,728,499.357912 mW

Electric Horsepower to Milliwatts

Formula to convert electric horsepower to milliwatts:

milliwatts = hp(E) × 746,000

Since one electric horsepower is equal to 746,000 milliwatts, the formula to find milliwatts is to multiply electric horsepower by 746,000.

For example, here's how to convert 5 electric horsepower to milliwatts using the formula.

5 hp(E) = (5 × 746,000) = 3,730,000 mW

Metric Horsepower to Milliwatts

Formula to convert metric horsepower to milliwatts:

milliwatts = hp(M) × 735,498.75

Since one metric horsepower is equal to 735,498.75 milliwatts, the formula to find milliwatts is to multiply metric horsepower by 735,498.75.

For example, here's how to convert 5 metric horsepower to milliwatts using the formula.

5 hp(M) = (5 × 735,498.75) = 3,677,493.75 mW

Boiler Horsepower to Milliwatts

Formula to convert boiler horsepower to milliwatts:

milliwatts = hp(S) × 9,809,500

Since one boiler horsepower is equal to 9,809,500 milliwatts, the formula to find milliwatts is to multiply boiler horsepower by 9,809,500.

For example, here's how to convert 5 boiler horsepower to milliwatts using the formula.

5 hp(S) = (5 × 9,809,500) = 49,047,500 mW

How Many Milliwatts Are in a Horsepower?

There are 745,699.871582 milliwatts in a horsepower, which is why we use this value in the formula above.

1 hp = 745,699.871582 mW

Horsepower and milliwatts are both units used to measure power. Keep reading to learn more about each unit of measure.

Horsepower

There are several types of horsepower, including mechanical, electrical, metric, boiler, brake, and indicated, and they all have different applications in industry. Mechanical and electrical are the most commonly used.

Mechanical Horsepower

Mechanical horsepower is often used to measure the output of engines and motors in North America. One mechanical horsepower is equal to 745.69987158227022 watts.

The mechanical horsepower is a US customary and imperial unit of power. Mechanical horsepower can be abbreviated as hp(I); for example, 1 mechanical horsepower can be written as 1 hp(I).

Electric Horsepower

Electric horsepower is used to measure the output of electric motors and other electrical machines in the US. One electric horsepower is equal to exactly 746 watts.

The electric horsepower is a US customary and imperial unit of power. Electric horsepower can be abbreviated as hp(E); for example, 1 electric horsepower can be written as 1 hp(E).

Metric Horsepower

One metric horsepower is the power needed to one metric horsepower as the lift a 75 kilogram mass at at one meter per second.^[1] One metric horsepower is equal to 735.49875 watts.

The metric horsepower is a non-SI metric unit for power. Metric horsepower can be abbreviated as hp(M), and are also sometimes abbreviated as PS, cv, hk, pk, ks, or ch. For example, 1 metric horsepower can be written as 1 hp(M), 1 PS, 1 cv, 1 hk, 1 pk, 1 ks, or 1 ch.

Boiler Horsepower

Boiler horsepower is used to measure the power of a boiler to generate steam. One boiler horsepower is equal to the power needed to evaporate 34.5 pounds in one hour.^[2]

Boiler horsepower can be abbreviated as hp(S); for example, 1 boiler horsepower can be written as 1 hp(S).

The term horsepower was adopted by Scottish inventor James Watt to measure the power output of his steam engine and to compare that power with that of horses horses.^[3] Horsepower were later used to measure the power output of piston and turbine engines and electrical motors.

Try our engine horsepower calculator to calculate the power of a motor.

Milliwatts

One milliwatt is the power equal to 1/1,000 of a watt, or the energy consumption at a rate of 1/1,000 of a joule per second.

The milliwatt is a multiple of the watt, which is the SI derived unit for power. In the metric system, "milli" is the prefix for thousandths, or 10^-3. Milliwatts can be abbreviated as mW; for example, 1 milliwatt can be written as 1 mW.

Milliwatts	Mechanical Horsepower	Electric Horsepower	Metric Horsepower	Boiler Horsepower
1 mW	0.000001341	0.0000013405	0.0000013596	0.00000010194
2 mW	0.000002682	0.000002681	0.0000027192	0.00000020388
3 mW	0.0000040231	0.0000040214	0.0000040789	0.00000030583
4 mW	0.0000053641	0.0000053619	0.0000054385	0.00000040777
5 mW	0.0000067051	0.0000067024	0.0000067981	0.00000050971
6 mW	0.0000080461	0.0000080429	0.0000081577	0.00000061165
7 mW	0.0000093872	0.0000093834	0.0000095174	0.00000071359
8 mW	0.000010728	0.000010724	0.000010877	0.00000081554
9 mW	0.000012069	0.000012064	0.000012237	0.00000091748
10 mW	0.00001341	0.000013405	0.000013596	0.0000010194
100 mW	0.000134	0.000134	0.000136	0.000010194
1000 mW	0.001341	0.00134	0.00136	0.000102
10000 mW	0.01341	0.013405	0.013596	0.001019
100000 mW	0.134102	0.134048	0.135962	0.010194
1000000 mW	1.341	1.3405	1.3596	0.101942

Horsepower to Milliwatts Converter

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