Authoritative definitions of the International System of Units and SI prefixes.
Dedicated unit pair
Watts to Mechanical horsepower
Convert W to hp instantly, then review the formula, assumptions, and rounding guidance.
Energy, work, heat & powerInstant result
Decimals
Formula result = input × 1 ÷ 745.699871582. 1 W = 0.0013 hp
Common examples
One value, several units
Kilowatts0.001 kW
Megawatts0 MW
Mechanical horsepower0.0013 hp
Metric horsepower0.0014 PS
BTU per hour3.4121 BTU/h
Conversion table
| W | hp |
|---|---|
| 1 W | 0.0013 hp |
| 2 W | 0.0027 hp |
| 5 W | 0.0067 hp |
| 10 W | 0.0134 hp |
| 25 W | 0.0335 hp |
| 50 W | 0.0671 hp |
| 100 W | 0.1341 hp |
Conversion chart
1 W0.0013 hp
5 W0.0067 hp
10 W0.0134 hp
25 W0.0335 hp
50 W0.0671 hp
Worked example
1 mechanical horsepower is approximately 745.7 watts.
Unit definition
Watts (W) One watts equals 1 watt.
Unit history
The watt is named for James Watt and is the SI unit of power, equal to one joule per second.
Step by step
1. Parse the value, including fractions.
2. Convert W to watt.
3. Convert the base value to hp and apply your display precision.
Understand the result before using it
Watts to Mechanical horsepower converts a value measured in Watts (W) into the equivalent value in Mechanical horsepower (hp). The numerical value changes because the size and definition of the selected unit changes; the underlying quantity does not.
Calculated result
The conversion follows the displayed unit relationship. Display rounding can hide additional digits, and measured inputs cannot become more accurate merely by changing units.
Formula, assumptions, and example
Formula
result = input × 1 ÷ 745.699871582
Assumptions
- Watts and Mechanical horsepower represent the same power quantity.
- The input is expressed in W; the output is expressed in hp.
- The unit definitions and conventional relationship shown on this page apply.
Worked example
1 W = 0.0013410220896 hp. For another value, apply the same relationship and round only to the precision your source measurement supports.
When to use it
Good uses
- Read a W measurement in a document that expects hp.
- Compare a watts value with a value reported in mechanical horsepower.
- Check the W-to-hp arithmetic before copying the result into another calculation.
Limitations
Common mistakes to avoid
- Do not confuse W with another unit that has a similar name or symbol.
- Round the output to a precision justified by the original measurement.
- Verify safety-critical, regulated, laboratory, and contractual conversions against the controlling standard.
Sources and further reading
These references explain the underlying standards or provide authoritative context. Your own contract, institution, clinician, product documentation, local code, or governing standard may be the controlling source.
Guidance on unit names, symbols, conversions, and numerical presentation.
Questions about this calculation
How do I convert Watts to Mechanical horsepower?
result = input × 1 ÷ 745.699871582 Using the displayed relationship, 1 W equals 0.0013410220896 hp.
How many Mechanical horsepower are in one Watts?
One Watts is 0.0013410220896 Mechanical horsepower. The displayed digits may be rounded.
Can I reverse the W to hp conversion?
Yes. Swap the source and target units in the converter. The reverse relationship converts hp back to W.
Is the Watts to Mechanical horsepower result exact?
The conversion follows the displayed unit relationship. Display rounding can hide additional digits, and measured inputs cannot become more accurate merely by changing units.