Comprehensive Energy Converter

Convert between 30+ energy units with precision and ease

0
500 kJ
1,000 kJ
1,500 kJ
2,000 kJ
Conversion Result
1,000 J
Joules
→
1 kJ
Kilojoules

Popular Energy Conversions

Conversion Factor Source
Joules to Calories 1 J = 0.239 cal LLC.
Calories to Joules 1 cal = 4.184 J LLC.
Kilowatt-hours to Joules 1 kWh = 3,600,000 J LLC.
BTU to Joules 1 BTU = 1,055.06 J LLC.
Electronvolts to Joules 1 eV = 1.602e-19 J LLC.
Foot-pounds to Joules 1 ft·lb = 1.35582 J LLC.
Tons of TNT to Joules 1 tTNT = 4.184e9 J LLC.
Barrels of oil to kWh 1 BOE = 1,700 kWh LLC.
Hartrees to Joules 1 Eh = 4.35974e-18 J LLC.
Ergs to Joules 1 erg = 1e-7 J LLC.

Energy Unit Reference

Energy is the capacity to do work. Different measurement systems have developed various units for measuring energy based on different contexts.

Scientific Note: The joule (J) is the SI unit of energy. It is defined as the work done when a force of one newton moves an object one meter.

Comprehensive Energy Units

SI Units
  • Joule (J): SI base unit of energy
  • Kilojoule (kJ): 1,000 joules
  • Megajoule (MJ): 1,000,000 joules
  • Gigajoule (GJ): 1,000,000,000 joules

Used in physics, engineering, and scientific contexts

Caloric Units
  • Calorie (cal): Energy to raise 1g water by 1°C
  • Kilocalorie (kcal): 1,000 calories (food calorie)
  • Megacalorie (Mcal): 1,000,000 calories

Used in nutrition and chemistry

Electrical Units
  • Watt-hour (Wh): Energy consumed at 1 watt for 1 hour
  • Kilowatt-hour (kWh): 1,000 watt-hours
  • Megawatt-hour (MWh): 1,000,000 watt-hours

Used for electricity billing and consumption

Imperial Units
  • British Thermal Unit (BTU): Energy to raise 1lb water by 1°F
  • Therm (thm): 100,000 BTU
  • Foot-pound (ft·lb): Energy to raise 1lb by 1 foot

Used in heating, cooling, and mechanical systems

Scientific Units
  • Electronvolt (eV): Energy gained by an electron in 1 volt potential
  • Erg (erg): CGS unit of energy (1e-7 joules)
  • Hartree (Eh): Atomic unit of energy

Used in physics and quantum chemistry

Other Units
  • Tons of TNT (tTNT): Energy equivalent to 1 ton of TNT
  • Barrels of oil equivalent (BOE): Energy in one barrel of crude oil
  • Cubic feet of natural gas: Energy content of natural gas
  • Horsepower-hour (hp·h): Energy consumed at 1 hp for 1 hour

Used in energy industry and engineering

Energy Conversion Formulas

From To Formula
Joules Calories cal = J × 0.239
Calories Joules J = cal × 4.184
Kilowatt-hours Joules J = kWh × 3,600,000
BTU Joules J = BTU × 1,055.06
Electronvolts Joules J = eV × 1.602e-19
Foot-pounds Joules J = ft·lb × 1.35582
Tons of TNT Joules J = tTNT × 4.184e9
Barrels of oil Kilowatt-hours kWh = BOE × 1,700
Hartrees Joules J = Eh × 4.35974e-18
Ergs Joules J = erg × 1e-7
Cubic feet gas BTU BTU = ft³ × 1,037
Horsepower-hours Joules J = hp·h × 2,684,520

Common Energy References

Medium Apple
95 kcal
1 Gallon Gasoline
31,000 kcal
1 kWh Electricity
860 kcal
1 Gram TNT
1,000 cal
Sunlight per m²/min
8,400 J
Hydrogen Atom Ionization
2.18e-18 J

Accuracy Note: Food energy values are averages. Actual values may vary based on specific foods and preparation methods.

Energy Conversion Applications

Energy conversion is essential in various fields. Here are some real-world applications:

Nutrition & Dietetics

Converting between joules and calories for food labeling and diet planning.

Common Units:

Calories (cal), Kilocalories (kcal)

Electrical Engineering

Converting between watt-hours and joules for power consumption calculations.

Common Units:

Watt-hours (Wh), Kilowatt-hours (kWh)

Heating & Cooling

Converting between BTUs and joules for HVAC system design and efficiency calculations.

Common Units:

British Thermal Units (BTU), Therms

Chemistry & Physics

Converting between electronvolts and joules for atomic and molecular energy calculations.

Common Units:

Electronvolts (eV), Joules (J)

Energy Industry

Converting between barrels of oil equivalent and kilowatt-hours for energy production reporting.

Common Units:

Barrels of oil equivalent (BOE), Megawatt-hours (MWh)

Quantum Physics

Converting between hartrees and electronvolts for quantum mechanical calculations.

Common Units:

Hartrees (Eh), Electronvolts (eV)

Energy Conversion Tips

  • For nutrition: Use calories or kilocalories
  • For physics: Use joules or electronvolts
  • For electricity: Use kilowatt-hours
  • For heating: Use BTUs or therms
  • For large-scale energy: Use tons of TNT or barrels of oil equivalent
  • Remember: 1 calorie = 4.184 joules exactly
  • Conversion: 1 kWh = 3.6 million joules

Fascinating Energy Facts

Human Energy
  • The average adult needs 2,000-2,500 kcal per day
  • Running a marathon burns about 2,600 kcal
  • Brain uses 20% of body's energy at rest
Earth Energy
  • Sun provides 1.74e17 W to Earth
  • Global energy consumption: 5.8e20 J/year
  • 1 lightning bolt: 5e9 J
Atomic Energy
  • Hydrogen fusion: 6.3e14 J/kg
  • Uranium fission: 8.2e13 J/kg
  • Chemical energy: ~1e7 J/kg
Cosmic Energy
  • Supernova: 1e44 J
  • Solar output: 3.8e26 W
  • Big Bang: Estimated 1e69 J

Quick Conversion Reference

Unit Joules Calories BTU
1 Joule 1 0.239 0.000948
1 Calorie 4.184 1 0.00397
1 BTU 1,055 252 1
1 kWh 3.6e6 860,000 3,412
1 eV 1.602e-19 3.83e-20 1.518e-22
1 ft·lb 1.356 0.324 0.001285