# Electron Mass Constant

Use Electron Mass in Calcul.io. See what this built-in constant represents, enter it in an editable calculation, and review related values and units.

## electronMass

Electron mass

Try it yourself:

```calculio
electronMass
```

---

## Electron Mass

**electronMass** is the rest mass of an electron, a key constant in atomic, quantum, and electromagnetic calculations.

## Mass and energy

Use it with [elementaryCharge](https://calcul.io/constants/elementaryCharge/index.md) and [bohrRadius](https://calcul.io/constants/bohrRadius/index.md). Rest mass differs from relativistic energy; use [speedOfLight](https://calcul.io/constants/speedOfLight/index.md) only in an appropriate energy relation.

[All constants](https://calcul.io/constants/index.md)