Energy Converter
Energy Converter: convert between 12 energy units, for example 1 kWh = 3412.141633 BTU.
| Unit | Value |
|---|---|
| kilowatt-hour to joule | 3600000 J |
| kilowatt-hour to kilojoule | 3600 kJ |
| kilowatt-hour to megajoule | 3.6 MJ |
| kilowatt-hour to calorie | 860420.6501 cal |
| kilowatt-hour to kilocalorie | 860.4206501 kcal |
| kilowatt-hour to watt-hour | 1000 Wh |
| kilowatt-hour (kWh) | 1 kWh |
| kilowatt-hour to British thermal unit | 3412.141633 BTU |
| kilowatt-hour to therm | 0.03412956341 thm |
| kilowatt-hour to electronvolt | 2.246943267 × 10²⁵ eV |
| kilowatt-hour to foot-pound | 2655223.737 ft·lbf |
| kilowatt-hour to erg | 36000000000000 erg |
Convert between joules, kilojoules, megajoules, calories, kilocalories, watt-hours, kilowatt-hours, BTU, therms, electronvolts, foot-pounds and ergs. Calories here are thermochemical (4.184 J) and the BTU is the International Table BTU.
Which calorie and which BTU?
The thermochemical calorie is exactly 4.184 J (used for food energy); the International Table calorie is 4.1868 J (used in steam tables and some HVAC data). The International Table BTU is exactly 1055.05585262 J; older "mean" and 59 °F BTUs differ by under 0.1 %.
Energy vs power
Energy is an amount (kWh, J, BTU); power is a rate (kW, W, BTU/h). A 2 kW heater running for 3 hours uses 6 kWh. Air-conditioner "BTU" ratings are really BTU per hour, a power.
Energy unit definitions
- joule (J)
- The joule (J) is the SI unit of energy, work and heat: the work done by a force of one newton over one metre, or one watt for one second.
- kilojoule (kJ)
- The kilojoule (kJ) is 1000 joules. Food labels in Australia, New Zealand and the EU give energy in kJ alongside kcal.
- megajoule (MJ)
- The megajoule (MJ) is one million joules. 3.6 MJ equals exactly 1 kWh.
- calorie (cal)
- The (thermochemical) calorie is exactly 4.184 J, roughly the heat needed to warm 1 g of water by 1 °C. The food "Calorie" is 1000 of these, a kilocalorie. Reference: Thermochemical calorie, 4.184 J exactly. The International Table calorie is 4.1868 J.
- kilocalorie (kcal)
- The kilocalorie (kcal) is 1000 calories, exactly 4184 J. Food labels call it a Calorie (capital C) or simply "calories". Reference: Thermochemical kilocalorie (food Calorie), 4184 J exactly.
- watt-hour (Wh)
- The watt-hour (Wh) is the energy of one watt for one hour, 3600 J. It is used for battery capacity.
- kilowatt-hour (kWh)
- The kilowatt-hour (kWh) is the energy of one kilowatt for one hour, exactly 3.6 MJ. Electricity is billed in kWh.
- British thermal unit (BTU)
- The British thermal unit (BTU) is roughly the heat needed to warm one pound of water by 1 °F. The International Table BTU is exactly 1055.05585262 J. Reference: International Table BTU (BTU_IT), 1055.05585262 J exactly.
- therm (thm)
- The US therm is 100 000 BTU, used to bill natural gas. NIST gives it as 105.4804 MJ, about 29.3 kWh. Reference: US therm, 100 000 BTU (59 °F), 105.4804 MJ as given by NIST SP 811. The EC therm is 105.506 MJ.
- electronvolt (eV)
- The electronvolt (eV) is the energy an electron gains across one volt, exactly 1.602176634 × 10⁻¹⁹ J since the 2019 SI redefinition.
- foot-pound (ft·lbf)
- The foot-pound (ft·lbf) is the work done by one pound-force over one foot, exactly 1.3558179483314004 J. As energy it is distinct from the torque unit pound-foot, although the factor is the same.
- erg (erg)
- The erg is the CGS unit of energy, one dyne-centimetre, exactly 10⁻⁷ J.
All energy conversions
From joules
From kilojoules
From megajoules
From calories
From kilocalories
From watt-hours
From kilowatt-hours
From British thermal units
From therms
From electronvolts
From foot-pounds
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- Printable energy conversion chart – print, PDF or PNG
- kW to hp (energy per unit time)
- BTU/h to watts for heating and cooling
- Ohm's Law Calculator – Any two of volts, amps, ohms and watts → the other two.
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Sources
- The International System of Units (SI), 9th edition (SI Brochure), Bureau International des Poids et Mesures.
- Guide for the Use of the International System of Units (SI), NIST Special Publication 811, 2008 Edition, National Institute of Standards and Technology.
Last reviewed: .