Physics Tool

E = mc² Calculator

Explore Einstein's theory of relativity by calculating the energy equivalent of mass.

Energy in Joules
8.9876e+16 J
In Kilowatt-hours (kWh)
2.4965e+10
Tons of TNT Equivalent
2.1481e+4 Kt

Calculated using c = 299,792,458 m/s

Σ The Formula

Energy (E) = mass (m) × speed of light (c)²

Real World Examples

One Kilogram
1 kg of mass is equivalent to ~90 Quadrillion Joules of energy.
Single Gram
Even a single gram contains enough energy to power a city for years.

# About This Calculator

Einstein's most famous equation, E = mc² (Mass-Energy Equivalence), states that energy and mass are the same thing, just in different forms. It shows that a very small amount of mass can be converted into a tremendous amount of energy.

In this formula:

  • E is the energy (Joules).
  • m is the mass (Kilograms).
  • c is the speed of light (~300,000,000 meters per second).
Because 'c' is such a large number and it is squared, the resulting energy 'E' is staggeringly high for even tiny masses.

How To Use

  1. Enter the **Mass** of the object.
  2. Select the **Unit** (kg, g, or lb).
  3. The **Joules**, **kWh**, and **TNT equivalent** are calculated instantly.
  4. Observe how the energy values change when you modify the mass.

Frequently Asked Questions

Does this mean I can turn mass into electricity?+

In theory, yes. Processes like nuclear fission (in power plants) and fusion (in the sun) work by converting a small fraction of mass into energy using exactly this principle.

Is the speed of light exact?+

Yes. The speed of light in a vacuum is defined as exactly 299,792,458 meters per second.

Is E = mc² Calculator free to use?+

Yes, E = mc² Calculator on Matheric is completely free to use. We believe in accessible education and utility for everyone.

How accurate is E = mc² Calculator?+

We use standard mathematical formulas and high-precision computing algorithms to ensure results for E = mc² Calculator are accurate for academic and professional use.

Can I use E = mc² Calculator on my phone?+

Yes! E = mc² Calculator is fully responsive and optimized for all devices, including smartphones, tablets, and desktops.

Do you save my data?+

No. We prioritize your privacy. All calculations are performed in your browser or temporarily processed, and we do not store your personal input data.

About

Einstein's most famous equation, E = mc² (Mass-Energy Equivalence), states that energy and mass are the same thing, just in different forms. It shows that a very small amount of mass can be converted into a tremendous amount of energy.

In this formula:

  • E is the energy (Joules).
  • m is the mass (Kilograms).
  • c is the speed of light (~300,000,000 meters per second).
Because 'c' is such a large number and it is squared, the resulting energy 'E' is staggeringly high for even tiny masses.

Related Tools