A kilowatt-hour (kWh) is the standard billing unit for electricity, equal to 1,000 watts sustained for one hour.
Kilowatt hours to Millijoules
Convert Kilowatt-hour (kWh) to Millijoule (mJ) instantly with an exact formula, conversion table, and FAQ.
Reserved for a responsive leaderboard above the conversion details.
Professional calculator style
World-scale conversion engine
30+ categories
6,500+ units
Instant results
Offline ready
Energy calculator
Energy Converter
Convert kilowatt hours (kWh) to millijoules (mJ) instantly with formula, conversion table, and FAQ.
Context values
Some unit families need one extra value for a physically accurate result.
A millijoule (mJ) is a metric-prefixed unit of energy equal to 10-3 joules, a fraction of a single joule, using the SI milli prefix.
mJ = kWh × 3600000000
Results update instantly for Kilowatt hours to Millijoules conversions.
Reserved above the conversion cards and below the converter.
Formula
mJ = kWh × 3600000000
kWh = mJ × 2.777777778e-10
Conversion table
| 1 kWh | 3.600000e+09 mJ |
| 5 kWh | 1.800000e+10 mJ |
| 10 kWh | 3.600000e+10 mJ |
| 20 kWh | 7.200000e+10 mJ |
| 50 kWh | 1.800000e+11 mJ |
| 100 kWh | 3.600000e+11 mJ |
| 500 kWh | 1.800000e+12 mJ |
| 1000 kWh | 3.600000e+12 mJ |
Related conversions
Reserved between the cards and the FAQ so the page stays balanced.
How the formula works
Both kilowatt-hour and millijoule measure the same physical quantity, so converting between them is a single multiplication. Multiply a value in kilowatt hours by 3600000000 to get millijoules. To reverse the conversion, multiply a millijoule value by 2.777777778e-10 to get back to kilowatt hours.
Frequently asked questions
What is Kilowatt-hour (kWh)?
A kilowatt-hour (kWh) is the standard billing unit for electricity, equal to 1,000 watts sustained for one hour.
What is Millijoule (mJ)?
A millijoule (mJ) is a metric-prefixed unit of energy equal to 10-3 joules, a fraction of a single joule, using the SI milli prefix.
How do I convert kilowatt hours to millijoules?
Multiply the kilowatt-hour value by 3600000000 to get the equivalent in millijoules. For example, 5 kWh × 3600000000 = 1.800000e+10 mJ.
Is this conversion exact?
Yes. Both units are defined against the SI base unit for this dimension, so the factor 3600000000 is an exact, non-rounded value.
Can I convert millijoules back to kilowatt hours?
Yes. Divide the millijoule value by 3600000000, or multiply it by 2.777777778e-10, to get kilowatt hours.
Reserved between the FAQ and the article so the page stays balanced.
About converting kilowatt hours to millijoules
A kilowatt-hour (kWh) is the standard billing unit for electricity, equal to 1,000 watts sustained for one hour. A millijoule (mJ) is a metric-prefixed unit of energy equal to 10-3 joules, a fraction of a single joule, using the SI milli prefix.
Use this calculator to move between kilowatt hours and millijoules accurately for homework, engineering, billing, or everyday energy calculations. The Universal Converter uses exact unit factors, so results stay consistent across the site.