Free Mass-Energy Equivalence Calculator

Calculate the energy equivalent of a mass using Einstein's famous equation: E = m * c^2.

kg

Energy

89,880,040,000,000,000.0000 J

Energy (MeV)561,048,938,826,466,900,000,000,000,000.0000 MeV
Energy (kWh)24,966,677,777.78 kWh

Energy vs Mass

Mass-Energy Equivalence

Einstein showed that mass and energy are interchangeable, related by the speed of light squared.

Formula

E = mc^2

  • *m* = mass in kg
  • *c* = 2.998 x 10^8 m/s
  • One kilogram of matter, if fully converted to energy, yields about 9 x 10^16 joules, roughly the energy of a 21-megaton nuclear weapon.

    Example Calculation

    Energy equivalent of 1 kg.

    1. 01E = mc^2
    2. 02E = 1 * (2.998e8)^2
    3. 03E = 8.988e16 J
    4. 04E = 2.497e10 kWh = 25 billion kWh

    Frequently Asked Questions

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