Energy Converter

Convert between joules, calories, BTU, kWh, and other energy units

Common Energy Conversions

Joule to Calorie
1 J = 0.239 cal
Kilowatt-hour to Megajoule
1 kWh = 3.6 MJ
BTU to Joule
1 BTU = 1055 J
Food Calorie to Joule
1 kcal = 4184 J
Watt-hour to Joule
1 Wh = 3600 J
Foot-pound to Joule
1 ft⋅lbf = 1.36 J

Energy in Everyday Life

Lightning Bolt

≈ 5 billion joules (1.4 MWh)

Food Calorie

1 dietary calorie = 4,184 joules

Car Fuel

1 gallon gasoline ≈ 132 MJ

Smartphone Battery

≈ 50 Wh (180,000 joules)

About Energy Measurement

Energy is the capacity to do work or cause change. It's measured in joules (J) in the SI system, though many other units are used in different contexts. Energy conversion calculations are fundamental in physics, engineering, nutrition, and energy management systems.

Common Applications

  • • Electrical energy consumption (kWh)
  • • Food and nutrition (calories)
  • • Fuel energy content (BTU, MJ)
  • • Battery capacity and storage
  • • Physics and engineering calculations
  • • Environmental impact assessment

Energy Forms

  • Kinetic: energy of motion
  • Potential: stored energy
  • Chemical: energy in bonds
  • Electrical: energy from electron flow
  • Thermal: heat energy
  • Nuclear: atomic energy

Energy Conservation

According to the law of conservation of energy, energy cannot be created or destroyed, only converted from one form to another. Understanding energy units helps in calculating efficiency, planning energy usage, and designing sustainable systems. 1 kWh of electrical energy equals 3.6 MJ.