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E = mc2 Calculator

E = mc2 Calculator
\( E = mc^2 \)
E =
speed of light

Calculator Use

The E = mc2 calculator uses the equation E = mc2, E equals m times c squared. Find the energy or mass of a system at rest when the other value is known.

The E = mc2 physics equation is known as the mass-energy equivalence relationship and you say it as "E equals m c squared."

You might also see the equation as E = mc^2 where the caret symbol means that 2 is an exponent and therefore c is squared.

E = mc2 Special Relativity Equation

This equation states that energy equals mass times the speed of light squared.

\( E = mc^2 \)


  • E = energy
  • m = mass
  • c = speed of light

The Meaning of E = mc2

The E = mc2 equation represents the idea that energy and mass are correlated, that any object with mass corresponds to an equivalent amount of energy. This equation is Einstein's special theory of relativity in mathematical terms.

The E = mc2 calculator can solve for E or m. If you know the mass of an object, m, you can solve for E, its intrinsic energy. Or if you have an amount of energy you can solve for m, its equivalent mass.

The speed of light is a constant and is displayed on the calculator as 299,792,458 meters per second. Often, some people round up and use 300,000,000 or 3e8 for ease of calculations. It this is you, you can change the value.


Cite this content, page or calculator as:

Furey, Edward "E = mc² Calculator" at https://www.calculatorsoup.com/calculators/physics/emc2.php from CalculatorSoup, https://www.calculatorsoup.com - Online Calculators

Last updated: October 9, 2023

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