Authoritative definitions of the International System of Units and SI prefixes.
Dedicated unit pair
Watts to Kilowatts
Convert W to kW instantly, then review the formula, assumptions, and rounding guidance.
Energy, work, heat & powerInstant result
Decimals
Formula result = input × 1 ÷ 1000. 1 W = 0.001 kW
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 | kW |
|---|---|
| 1 W | 0.001 kW |
| 2 W | 0.002 kW |
| 5 W | 0.005 kW |
| 10 W | 0.01 kW |
| 25 W | 0.025 kW |
| 50 W | 0.05 kW |
| 100 W | 0.1 kW |
Conversion chart
1 W0.001 kW
5 W0.005 kW
10 W0.01 kW
25 W0.025 kW
50 W0.05 kW
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 kW and apply your display precision.
Understand the result before using it
Watts to Kilowatts converts a value measured in Watts (W) into the equivalent value in Kilowatts (kW). 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 ÷ 1000
Assumptions
- Watts and Kilowatts represent the same power quantity.
- The input is expressed in W; the output is expressed in kW.
- The unit definitions and conventional relationship shown on this page apply.
Worked example
1 W = 0.001 kW. 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 kW.
- Compare a watts value with a value reported in kilowatts.
- Check the W-to-kW 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 Kilowatts?
result = input × 1 ÷ 1000 Using the displayed relationship, 1 W equals 0.001 kW.
How many Kilowatts are in one Watts?
One Watts is 0.001 Kilowatts. The displayed digits may be rounded.
Can I reverse the W to kW conversion?
Yes. Swap the source and target units in the converter. The reverse relationship converts kW back to W.
Is the Watts to Kilowatts 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.