What is the standard SI base or derived unit for energy?

In the International System of Units (SI), energy is quantified relative to fundamental physical standards defined by BIPM. UnitGlide references these exact metric constants for all calculations.

How many energy units can I convert on UnitGlide?

UnitGlide currently supports 54 different energy units, including SI metric, British Imperial, US Customary, and scientific standard units.

How do I convert between different energy units?

Enter your known value into the 'Convert from' field, choose your starting unit, and select your target unit. UnitGlide computes the answer instantly using 12-digit floating point arithmetic.

Energy Converter

Convert energy units including joule, kilojoule, kilowatt-hour, watt-hour, calorie (nutritional) and many more energy units instantly and accurately.

From

0.01

10 joules (J) = 0.01 kilojoules (kJ)

Decimal places:

Formula:

kJ = J × 0.001

Popular Energy Conversions

Quick access to the most commonly used energy conversions.

About Energy Units

Free online energy converter - converts between 55 units of energy, including joule [J], kilojoule [kJ], kilowatt-hour [kW*h], watt-hour [W*h], etc. Also, explore many other unit converters or learn more about energy unit conversions. Different unit systems are used worldwide, including the Metric System (SI) and the Imperial / US Customary System.

Metric System (SI)

The metric system is the most widely adopted international measurement standard. The base unit is the joule.

Imperial System (US)

The imperial system is commonly used in the United States and specialized international industries including aviation and maritime navigation.

Common Energy Units

Here are some of the most common energy units and their abbreviations.

Unit	Symbol	Type	In Joule
Joule	J	Metric (base)	1 J
Kilojoule	kJ	Metric	1000 J
Kilowatt-hour	kW*h	Metric	3600000 J
Watt-hour	W*h	Metric	3600 J
Calorie (nutritional)	—	Standard	4186.8 J
Horsepower (metric) hour	—	Standard	2647795.5 J
Btu (IT)	Btu (IT), Btu	Standard	1055.055853 J
Btu (th)	Btu (th)	Standard	1054.35 J
Gigajoule	GJ	Metric	1000000000 J
Megajoule	MJ	Metric	1000000 J