E = mc² Calculator
Calculate mass-energy equivalence using Einstein's famous equation from special relativity
Calculate Mass-Energy Equivalence
Enter the mass to calculate its rest energy equivalent
Preset Scenarios
E = mc² Results
Energy Comparisons
Einstein's Mass-Energy Equivalence
Physics Interpretation
Example: Average Human Mass
Given Values
Mass: 62 kg (average adult human)
Speed of light: c = 299,792,458 m/s
c²: 8.99 × 10¹⁶ m²/s²
Calculation
E = mc²
E = 62 kg × (2.998 × 10⁸ m/s)²
E = 62 kg × 8.99 × 10¹⁶ m²/s²
E = 5.57 × 10¹⁸ joules = 5.57 exajoules
Equivalent to: ~66,000 atomic bombs (Nagasaki-sized)
Einstein's Insight
Albert Einstein's 1905 equation revealed that mass and energy are interchangeable.
Even a tiny amount of mass contains enormous energy due to c² (speed of light squared).
This principle explains nuclear reactions, stellar fusion, and the source of all atomic energy.
Physical Constants
Real-World Applications
Nuclear Power
Converting tiny amounts of mass into enormous energy
Stellar Fusion
How stars convert hydrogen to helium and produce energy
Medical Imaging
PET scans using electron-positron annihilation
Particle Physics
Creating new particles by converting energy to mass
Space Technology
Understanding mass-energy for advanced propulsion
Understanding E = mc²
What Does E = mc² Mean?
Einstein's equation reveals that mass (m) and energy (E) are fundamentally the same thing, related by the speed of light squared (c²). This means that any object with mass contains a tremendous amount of rest energy, even when it's not moving.
Why c²?
The speed of light (c) is approximately 300 million meters per second. When squared, this becomes about 9 × 10¹⁶ m²/s². This enormous number explains why even tiny amounts of mass correspond to huge amounts of energy.
Historical Impact
Published in 1905 as part of Einstein's special theory of relativity, this equation revolutionized physics and led to the development of nuclear power, nuclear weapons, and our understanding of stellar processes.
Mass-Energy Conservation
The equation shows that mass and energy are conserved together, not separately. In nuclear reactions, a small amount of mass can be converted to energy, or high-energy processes can create new particles (mass) from pure energy.
Consequences and Applications
Nuclear Reactions
Nuclear fission and fusion convert small amounts of mass into enormous energy, powering both nuclear reactors and the sun.
Particle Creation
High-energy collisions can create new particles from pure energy, demonstrating mass-energy equivalence in reverse.
Binding Energy
The "mass defect" in atomic nuclei represents binding energy that holds protons and neutrons together.