How do you convert metric horsepower to milliwatts?

To convert metric horsepower (PS) to milliwatts (mW), multiply the power in metric horsepower by 735,498.75 (milliwatts = metric horsepower × 735,498.75).

What is 5 metric horsepower in milliwatts?

5 metric horsepower (5 PS) is equal to 3,677,493.75 milliwatts (3,677,493.75 mW).

Which is larger, 1 horsepower (metric ps) (PS) or 1 milliwatt (mW)?

One horsepower (metric ps) (PS) is larger than one milliwatt (mW). Specifically, 1 PS contains 735,498.75 mW, whereas 1 mW is 0.00000135 PS.

How do I convert back from milliwatts (mW) to metric horsepower (PS)?

To reverse the calculation from mW to PS, multiply your milliwatt value by the inverse factor 0.00000135 (or divide by 735,498.75). You can also click the Swap button in the tool above to flip directions in one click.

How many decimal places should I round PS to mW results to?

For everyday comparisons and quick estimates, rounding to 2 decimal places is usually sufficient (for example, 5 PS ≈ 3,677,493.75 mW). For engineering, laboratory, or machining specifications, select 4 or 6 decimals—or Scientific (10ⁿ) mode—in the calculator toolbar above.

Metric Horsepower to Milliwatts Converter

Enter the power in metric horsepower below to convert it to milliwatts.

Milliwatts to Metric Horsepower (mW → PS)

Convert Metric Horsepower to Milliwatts

Enter a value in metric horsepower (PS) to convert to milliwatts (mW).

Value (PS)

From

Result

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3,677,493.75milliwatts

5 PS = 3,677,493.75 mW

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Suggested Conversions

Reference:NIST SP 811 (NIST SP 811 App. B.9 (Power & Radiant Flux))

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Horsepower to Milliwatt Conversion Table

Table showing various horsepower measurements converted to milliwatts. Click any preset value or arrow to load it into the converter.

Metric Horsepower (PS)	Milliwatts (mW)
0.0000001 PS	0.0735499 mW
0.0000002 PS	0.1470998 mW
0.0000003 PS	0.2206496 mW
0.0000004 PS	0.2941995 mW
0.0000005 PS	0.3677494 mW
0.0000006 PS	0.4412992 mW
0.0000007 PS	0.5148491 mW
0.0000008 PS	0.588399 mW
0.0000009 PS	0.6619489 mW
0.00000001 PS	0.007355 mW

How to Convert Metric Horsepower to Milliwatts

To convert metric horsepower to milliwatts, multiply the power by the following conversion ratio: 735,498.75 milliwatts/horsepower.

Since one horsepower is equal to 735,498.75 milliwatts, you can use this simple formula to convert:

milliwatts = metric horsepower × 735,498.75

The power in milliwatts is equal to the power in metric horsepower multiplied by 735,498.75.

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

milliwatts = (5 PS × 735,498.75) = 3,677,493.75 mW

How Many Milliwatts Are in a Horsepower?

There are 735,498.75 milliwatts in a horsepower, which is why we use this value in the formula above.

1 PS = 735,498.75 mW|1 mW = 0.00000136 PS

Our horsepower to milliwatt calculator automatically converts your power measurements with full decimal and scientific precision across US customary, imperial, and SI metric standards.

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

What Is a Horsepower?

A horsepower is a unit of power equal to 735.49875 watts (W), the base unit for power. Metric horsepower (75 kgf·m/s = 735.49875 W). [1]

The horsepower is classified as a metric and SI-compatible unit of power. Metric Horsepower can be abbreviated as PS; for example, 1 horsepower can be written as 1 PS.

When working with metric horsepower (PS) in formulas or technical specifications, always verify whether your target system uses SI metric, US customary, or British imperial standards.

In practice, metric horsepower (PS) are widely used across standard power applications within SI metric workflows, engineering documentation, and technical data sheets.

Learn more about metric horsepower in our Power Converter.

What Is a Milliwatt?

A milliwatt is a unit of power equal to 1/1,000 of a watt (0.001 W). One-thousandth of a Watt. [2]

The milliwatt is classified as a metric and SI-compatible unit of power. Milliwatts can be abbreviated as mW; for example, 1 milliwatt can be written as 1 mW.

In the metric system, "milli" is the standard SI prefix for thousandths, or 10⁻³. This makes the milliwatt (mW) a convenient decimal multiple of the watt (W).

In practice, milliwatts (mW) are widely used across fine-tolerance laboratory, analytical, and micro-scale power measurements within SI metric workflows, engineering documentation, and technical data sheets.

Learn more about milliwatts in our Power Converter.

When converting power between metric horsepower (PS) and milliwatts (mW), keep full floating-point precision (1 PS = 735,498.75 mW; 1 mW = 0.00000136 PS) during intermediate calculations and round only the final milliwatt figure to match your instrument tolerance.

More Horsepower & Milliwatt Conversions

Need to calculate in the opposite direction? Use our milliwatts to metric horsepower calculator to switch your starting unit immediately. You can also explore related tools such as converting milliwatts to metric horsepower, converting metric horsepower to horsepower (hp), or converting metric horsepower to kilowatts.

Convert from Metric Horsepower

Convert to Milliwatts

Frequently Asked Questions

There are 735,498.75 milliwatts (mW) in 1 horsepower (PS). Conversely, 1 milliwatt (mW) is equal to 0.00000135 metric horsepower (PS).

Power Converter

Quick Info

Direct Factor: 1 horsepower (metric ps) (PS) equals 735,498.75 milliwatts (mW).
Inverse Factor: 1 milliwatt (mW) equals 0.00000135 metric horsepower (PS).
Formula: milliwatts = metric horsepower × 735,498.75.
Verified Precision: Anchored to official NIST SP 811 and ISO/IEC 80000 standards.

Units Comparison

Horsepower (Metric PS) (PS)

Metric horsepower (75 kgf·m/s = 735.49875 W).

Milliwatt (mW)

One-thousandth of a Watt.

Watt (W)

Coherent SI unit of power equal to 1 Joule per second (1 J/s).

References

[1]NIST SP 811 · NIST SP 811 App. B.9 (Power & Radiant Flux)
Source
[2]NIST CUU · Derived SI Unit: Watt (W)
Source
[3]BIPM · SI Brochure (9th Ed.) — Power
Source

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References

NIST · BIPM · ISO

[1]
NIST SP 811 (NIST SP 811 App. B.9 (Power & Radiant Flux))·Power Metrology Standard — Metric Horsepower (PS) to Milliwatts (mW)
NIST SP 811 Standard
[2]
NIST CUU (Derived SI Unit: Watt (W))·Unit Specifications: Horsepower (Metric PS) (PS) & Milliwatt (mW)
NIST CUU Specification
[3]
BIPM (SI Brochure (9th Ed.) — Power)·Conversion Factors & Mathematical Basis (PS to mW)
BIPM Reference

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