Calculator
Convert single-particle or total particle energy between mega electron volts and joules with uncertainty, notation controls, and a dynamic graph.
Plotly Graph
The graph shows the conversion relationship across a range around your chosen input or the automatic scale.
Example Data Table
| Energy (MeV) | Equivalent Energy (J) |
|---|---|
| 0.5 | 8.01088317 × 10^-14 |
| 1 | 1.602176634 × 10^-13 |
| 5 | 8.01088317 × 10^-13 |
| 10 | 1.602176634 × 10^-12 |
| 100 | 1.602176634 × 10^-11 |
Formula Used
One electron volt equals 1.602176634 × 10-19 joules. Since one mega electron volt equals one million electron volts, one MeV equals 1.602176634 × 10-13 joules.
Forward conversion: Joules = MeV × 1.602176634 × 10-13
Reverse conversion: MeV = Joules ÷ 1.602176634 × 10-13
Total energy: Total converted energy = per-particle converted energy × particle count
Uncertainty: Absolute uncertainty = converted value × uncertainty percent ÷ 100
How to Use This Calculator
- Select the conversion direction.
- Enter the energy value in the selected source unit.
- Add particle count when total energy is needed.
- Enter optional uncertainty percent for error bands.
- Choose significant figures and notation style.
- Set a custom graph upper limit if desired.
- Press Convert Now to view results above the form.
- Use CSV or PDF buttons to export your output.
Frequently Asked Questions
1) What is a mega electron volt?
A mega electron volt is an energy unit equal to one million electron volts. Physicists use it for particle, nuclear, and radiation energy scales.
2) How many joules are in 1 MeV?
One MeV equals 1.602176634 × 10-13 joules. This constant comes directly from the exact SI definition of the electron volt.
3) Why convert MeV to joules?
Joules are the SI unit of energy. Converting lets you compare particle energies with laboratory, engineering, and thermodynamic calculations more easily.
4) Can this calculator convert joules back to MeV?
Yes. Switch the conversion mode to Joule to Mega Electron Volt. The page then uses the inverse of the MeV-to-joule constant.
5) What does particle count change?
Particle count multiplies the converted single-particle energy. It is useful when you need total energy for many identical particles or events.
6) What is the uncertainty field for?
It estimates an upper and lower range around the converted value. This helps when your measured energy has experimental tolerance or rounding limits.
7) Which notation should I choose?
Scientific notation is best for very small or large values. Engineering notation groups exponents by three. Fixed notation suits simple decimal display.
8) Is the conversion linear?
Yes. The relationship is perfectly linear because the conversion uses a fixed constant. Doubling MeV exactly doubles the corresponding joule value.