Energy Unit Converter | Convert between Joules, Calories, Kilowatt-hours and more
Online energy unit converter that supports precise conversion between joules, calories, kilowatt-hours, BTU and more energy units, providing professional results and reference knowledge.
Energy Unit Knowledge
Basic Energy Units
Energy is a physical quantity that represents the capacity to do work. The basic energy unit in the International System of Units (SI) is the joule (J), defined as the work done by a force of 1 newton moving an object 1 meter in the direction of the force.
Common Energy Unit Conversions
- 1 kilojoule (kJ) = 1000 joules (J)
- 1 calorie (cal) = 4.184 joules (J)
- 1 kilocalorie (kcal) = 4184 joules (J)
- 1 kilowatt-hour (kWh) = 3,600,000 joules (J) = 3.6 megajoules (MJ)
- 1 British Thermal Unit (BTU) = 1055.06 joules (J)
- 1 electronvolt (eV) = 1.602176634×10^-19 joules (J).
Heat Units
- Calories (cal) and British Thermal Units (BTU) are primarily used to measure heat energy. The food calorie (Cal, also known as the large calorie) is actually a kilocalorie (kcal), commonly used in food nutrition labels. 1 kilocalorie (kcal) = 1 food calorie (Cal) = 4.184 kilojoules (kJ)
- 1 BTU is the amount of heat needed to raise the temperature of 1 pound of water by 1°F.
Electrical Energy Units
Watt-hours (Wh) and kilowatt-hours (kWh) are common units for electrical energy. 1 watt-hour represents the energy consumed by a device with a power of 1 watt operating for 1 hour, equal to 3600 joules. The kilowatt-hour is the standard unit for electricity billing, with 1 kilowatt-hour (kWh) = 1000 watt-hours (Wh) = 3.6 megajoules (MJ).
Energy Resource Units
- Ton of oil equivalent (toe), ton of coal equivalent (tce), and TNT equivalent are units for measuring large-scale energy resources and explosive energy. 1 ton of oil equivalent is approximately 41.868 gigajoules
- 1 ton of TNT equivalent is approximately 4.184 gigajoules, commonly used to express nuclear weapon yields
- Barrel of oil equivalent is used in the petroleum industry, with 1 barrel of oil being approximately 6.1 gigajoules.
Energy Units in Different Fields
- In physics, joules (J) and ergs are commonly used
- In nutrition, calories (cal) and kilocalories (kcal) are used
- The power industry uses kilowatt-hours (kWh) and megawatt-hours (MWh)
- Nuclear physics uses electronvolts (eV) and its multiples
- The energy industry uses barrels of oil equivalent, tons of oil equivalent, etc.
- The HVAC industry commonly uses British Thermal Units (BTU).