E = mc² Calculator - Mass-Energy Equivalence

Your details

Forward: give a mass, get the rest energy. Reverse: give an energy, get the equivalent mass.
The object's rest mass. Any positive value works.
Choose the unit that matches your input.
The unit used for the primary energy output. All secondary comparisons are always shown.
Result
8.988 x 10^16 J

Energy (forward mode) or mass (reverse mode) in your chosen unit.

Energy in joules8.988 x 10^16 J
Energy in kWh2.497 x 10^10 kWh
Megatons of TNT2.148 x 10^1 Mt TNT
Mass in kg1.000 x 10^0 kg
Mass in atomic mass units6.022 x 10^26 u

Rest energy: 8.988 x 10^16 J

  • Equivalent to 1.43e+3 Hiroshima-scale atomic bombs (~63 TJ each).
  • That is enough electricity for about 2.31e+6 average US homes for one year.
  • The mass equivalent is 1.0000 kg.
  • The Sun outputs this much energy in about 2.35e-7 milliseconds.

Next stepRemember: this is rest energy only. An object moving at high speed also has relativistic kinetic energy on top of this. For particle-physics calculations, use the MeV output unit.

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