Authoritative definitions of the International System of Units and SI prefixes.
Dedicated unit pair
Kilowatt-hours to Watt-hours
Convert kWh to Wh instantly, then review the formula, assumptions, and rounding guidance.
Energy, work, heat & powerInstant result
Decimals
Formula result = input × 3600000 ÷ 3600. 1 kWh = 1,000 Wh
Common examples
One value, several units
Joules3,600,000 J
Kilojoules3,600 kJ
Megajoules3.6 MJ
Watt-hours1,000 Wh
Thermochemical calories860,420.6501 cal
Kilocalories860.4207 kcal
BTU (International Table)3,412.1416 BTU
Conversion table
| kWh | Wh |
|---|---|
| 1 kWh | 1,000 Wh |
| 2 kWh | 2,000 Wh |
| 5 kWh | 5,000 Wh |
| 10 kWh | 10,000 Wh |
| 25 kWh | 25,000 Wh |
| 50 kWh | 50,000 Wh |
| 100 kWh | 100,000 Wh |
Conversion chart
1 kWh1,000 Wh
5 kWh5,000 Wh
10 kWh10,000 Wh
25 kWh25,000 Wh
50 kWh50,000 Wh
Worked example
1 kilowatt-hour equals exactly 3.6 megajoules.
Unit definition
Kilowatt-hours (kWh) One kilowatt-hours equals 3,600,000 joule.
Unit history
Kilowatt-hours is represented here using its modern SI definition or an internationally accepted relationship to an SI base unit.
Step by step
1. Parse the value, including fractions.
2. Convert kWh to joule.
3. Convert the base value to Wh and apply your display precision.
Understand the result before using it
Kilowatt-hours to Watt-hours converts a value measured in Kilowatt-hours (kWh) into the equivalent value in Watt-hours (Wh). 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 × 3600000 ÷ 3600
Assumptions
- Kilowatt-hours and Watt-hours represent the same energy, work & heat quantity.
- The input is expressed in kWh; the output is expressed in Wh.
- The unit definitions and conventional relationship shown on this page apply.
Worked example
1 kWh = 1,000 Wh. 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 kWh measurement in a document that expects Wh.
- Compare a kilowatt-hours value with a value reported in watt-hours.
- Check the kWh-to-Wh arithmetic before copying the result into another calculation.
Limitations
Common mistakes to avoid
- Do not confuse kWh 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 Kilowatt-hours to Watt-hours?
result = input × 3600000 ÷ 3600 Using the displayed relationship, 1 kWh equals 1,000 Wh.
How many Watt-hours are in one Kilowatt-hours?
One Kilowatt-hours is 1,000 Watt-hours. The displayed digits may be rounded.
Can I reverse the kWh to Wh conversion?
Yes. Swap the source and target units in the converter. The reverse relationship converts Wh back to kWh.
Is the Kilowatt-hours to Watt-hours 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.