Authoritative definitions of the International System of Units and SI prefixes.
Dedicated unit pair
Kilowatt-hours to Megajoules
Convert kWh to MJ instantly, then review the formula, assumptions, and rounding guidance.
Energy, work, heat & powerInstant result
Decimals
Formula result = input × 3600000 ÷ 1000000. 1 kWh = 3.6 MJ
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 | MJ |
|---|---|
| 1 kWh | 3.6 MJ |
| 2 kWh | 7.2 MJ |
| 5 kWh | 18 MJ |
| 10 kWh | 36 MJ |
| 25 kWh | 90 MJ |
| 50 kWh | 180 MJ |
| 100 kWh | 360 MJ |
Conversion chart
1 kWh3.6 MJ
5 kWh18 MJ
10 kWh36 MJ
25 kWh90 MJ
50 kWh180 MJ
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 MJ and apply your display precision.
Understand the result before using it
Kilowatt-hours to Megajoules converts a value measured in Kilowatt-hours (kWh) into the equivalent value in Megajoules (MJ). 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 ÷ 1000000
Assumptions
- Kilowatt-hours and Megajoules represent the same energy, work & heat quantity.
- The input is expressed in kWh; the output is expressed in MJ.
- The unit definitions and conventional relationship shown on this page apply.
Worked example
1 kWh = 3.6 MJ. 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 MJ.
- Compare a kilowatt-hours value with a value reported in megajoules.
- Check the kWh-to-MJ 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 Megajoules?
result = input × 3600000 ÷ 1000000 Using the displayed relationship, 1 kWh equals 3.6 MJ.
How many Megajoules are in one Kilowatt-hours?
One Kilowatt-hours is 3.6 Megajoules. The displayed digits may be rounded.
Can I reverse the kWh to MJ conversion?
Yes. Swap the source and target units in the converter. The reverse relationship converts MJ back to kWh.
Is the Kilowatt-hours to Megajoules 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.