Energy Unit Converter

Convert between different energy units like btu, calories, joules...etc

Energy is the fundamental capacity to do work and exists in many forms—kinetic, potential, thermal, electrical, chemical, and nuclear. From the calories in your food to the kilowatt-hours on your electric bill, energy measurements are everywhere. Our converter handles scientific units (joules), practical units (kWh, BTU), nutritional units (calories), and more.

History & Background

The concept of energy was formalized in the 19th century. James Prescott Joule demonstrated the mechanical equivalent of heat, leading to the unit being named after him. The calorie was defined for measuring heat, while the BTU served similar purposes in the British Imperial system. Today, the joule is the SI standard, but many practical applications retain historical units.

How to Convert

kWh to Joules
joules = kWh × 3,600,000

Multiply kilowatt-hours by 3.6 million to get joules.

Example: 1 kWh × 3,600,000 = 3,600,000 J (3.6 MJ)

Calories to Joules
joules = calories × 4.184

Multiply calories by 4.184 to get joules.

Example: 100 cal × 4.184 = 418.4 J

BTU to kWh
kWh = BTU × 0.000293

Multiply BTU by 0.000293 to get kilowatt-hours.

Example: 10,000 BTU × 0.000293 = 2.93 kWh

Joules to Watt-hours
Wh = joules ÷ 3,600

Divide joules by 3,600 to get watt-hours.

Example: 7,200 J ÷ 3,600 = 2 Wh

Real-World Examples

Daily Human Food Intake

Average adult daily energy intake is about 2,000 kilocalories (food Calories).

2,000 kcal=8.37 MJ
Smartphone Battery

A typical smartphone battery holds about 10-15 watt-hours of energy.

12 Wh=43,200 J
Gallon of Gasoline

One gallon of gasoline contains approximately 120 MJ of chemical energy.

120 MJ=33.3 kWh
Home Air Conditioner

A 12,000 BTU/hour air conditioner rating indicates its cooling capacity.

12,000 BTU=12.66 MJ
Monthly Electricity Usage

Average US household uses about 900 kWh of electricity per month.

900 kWh=3,240 MJ
Lightning Bolt

A typical lightning bolt releases about 1 billion joules of energy.

1 GJ=277.8 kWh

Did You Know?

  • •The Sun produces 384.6 yottajoules (3.846 × 10²⁶ watts) of energy per second—enough to power Earth for billions of years.
  • •A single chocolate chip cookie contains about 50 kilocalories, enough energy to power a 60W light bulb for about 35 minutes.
  • •The energy released by the atomic bomb dropped on Hiroshima was approximately 63 terajoules (15 kilotons of TNT equivalent).
  • •Your brain uses about 20% of your daily caloric intake—roughly 400 kcal—despite being only 2% of your body weight.
  • •One gallon of gasoline contains the same energy as about 33.7 kWh of electricity, but internal combustion engines waste 70-80% as heat.

Energy conversion table

1 J = 0.0009484516526770049 BTU1 joules equals 0.0009484516526770049 Btu (th)1 * 0.0009484516526770049 = X BTU
1 J = 0.0009470862890317938 BTU1 joules equals 0.0009470862890317938 Btu (mean)1 * 0.0009470862890317938 = X BTU
1 J = 0.23884589662749595 cal1 joules equals 0.23884589662749595 calories (IT)1 * 0.23884589662749595 = X cal
1 J = 0.2390057361376673 cal1 joules equals 0.2390057361376673 calories (th)1 * 0.2390057361376673 = X cal
1 J = 0.23866234528713468 cal1 joules equals 0.23866234528713468 calories (mean)1 * 0.23866234528713468 = X cal
1 J = 0.2389029576186153 cal1 joules equals 0.2389029576186153 calories (15C)1 * 0.2389029576186153 = X cal
1 J = 0.2391257562352041 cal1 joules equals 0.2391257562352041 calories (20C)1 * 0.2391257562352041 = X cal
1 J = 0.00023889154323936931 kcal1 joules equals 0.00023889154323936931 calories (food)1 * 0.00023889154323936931 = X kcal
1 J = 0.0005262050094716901 CHU1 joules equals 0.0005262050094716901 centigrade heat units1 * 0.0005262050094716901 = X CHU
1 J = 3.15955766192733e-8 m³1 joules equals 3.15955766192733e-8 Dutch natural gas (m³ - LHV)1 * 3.15955766192733e-8 = X m³
1 J = 6241457005723417000 eV1 joules equals 6241457005723417000 electron volts1 * 6241457005723417000 = X eV
1 J = 10000000 erg1 joules equals 10000000 ergs1 * 10000000 = X erg
1 J = 1e-18 EJ1 joules equals 1e-18 exajoules1 * 1e-18 = X EJ
1 J = 0.7375621492772654 ft lbs1 joules equals 0.7375621492772654 foot-pound force1 * 0.7375621492772654 = X ft lbs
1 J = 23.730422401518748 ft pdl1 joules equals 23.730422401518748 foot poundals1 * 23.730422401518748 = X ft pdl
1 J = 2.9239766081871347e-8 L1 joules equals 2.9239766081871347e-8 gasoline (L)1 * 2.9239766081871347e-8 = X L
1 J = 1e-9 GJ1 joules equals 1e-9 gigajoules1 * 1e-9 = X GJ
1 J = 2.777777777777778e-13 GWh1 joules equals 2.777777777777778e-13 gigawatt hours1 * 2.777777777777778e-13 = X GWh
1 J = 3.7250607184897115e-7 hp h1 joules equals 3.7250607184897115e-7 horsepower hours1 * 3.7250607184897115e-7 = X hp h
1 J = 8.850745791327185 in lbf1 joules equals 8.850745791327185 inch-pound force1 * 8.850745791327185 = X in lbf
1 J = 0.00023884589662749592 kcal1 joules equals 0.00023884589662749592 kilocalories (IT)1 * 0.00023884589662749592 = X kcal
1 J = 0.0002390057361376673 kcal1 joules equals 0.0002390057361376673 kilocalories (th)1 * 0.0002390057361376673 = X kcal
1 J = 0.10197162129779283 kgf m1 joules equals 0.10197162129779283 kilogram-force meters1 * 0.10197162129779283 = X kgf m
1 J = 0.001 kJ1 joules equals 0.001 kilojoules1 * 0.001 = X kJ
1 J = 2.7777777777777776e-7 kWh1 joules equals 2.7777777777777776e-7 kilowatt hours1 * 2.7777777777777776e-7 = X kWh
1 J = 0.000001 MJ1 joules equals 0.000001 megajoules1 * 0.000001 = X MJ
1 J = 2.7777777777777777e-10 MWh1 joules equals 2.7777777777777777e-10 megawatt hours1 * 2.7777777777777777e-10 = X MWh
1 J = 1 Nm1 joules equals 1 newton meters1 * 1 = X Nm
1 J = 1e-15 PJ1 joules equals 1e-15 petajoules1 * 1e-15 = X PJ
1 J = 1e-12 TJ1 joules equals 1e-12 terajoules1 * 1e-12 = X TJ
1 J = 2.777777777777778e-16 TWh1 joules equals 2.777777777777778e-16 terawatt hours1 * 2.777777777777778e-16 = X TWh
1 J = 9.478171203551087e-9 thm1 joules equals 9.478171203551087e-9 therms1 * 9.478171203551087e-9 = X thm
1 J = 1 Ws1 joules equals 1 watt seconds1 * 1 = X Ws
1 J = 0.0002777777777777778 Wh1 joules equals 0.0002777777777777778 watt hours1 * 0.0002777777777777778 = X Wh

F.A.Q. - Frequently Asked Questions

Popular energy Conversions

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