Elementary charge (e)
The charge of one proton, exactly 1.602176634 × 10⁻¹⁹ C (an SI defining constant).
What is an elementary charge?
- Symbol
- e
- Quantity
- Electric Charge
- Unit system
- SI
- Definition
- The charge of one proton, exactly 1.602176634 × 10⁻¹⁹ C (an SI defining constant).
- Exact
- Yes, the value is exact by definition
- Source
- SI Brochure, 9th edition (BIPM, 2019)
Common applications
Used in atomic, particle and semiconductor physics, where charges are counted in multiples of the charge of one proton.
Elementary charge in other electric charge units
- 1 e = 1.602176634e-19 CCoulomb
- 1 e = 1.602176634e-16 mCMillicoulomb
- 1 e = 1.602176634e-13 µCMicrocoulomb
- 1 e = 1.602176634e-10 nCNanocoulomb
- 1 e = 4.45049065e-23 AhAmpere-hour
- 1 e = 4.45049065e-20 mAhMilliampere-hour
- 1 e ≈ 1.660539067e-24 F (charge)Faraday (charge)
- 1 e = 1.602176634e-20 abCAbcoulomb
- 1 e = 4.80320471257026372e-10 statCStatcoulomb
Elementary charge quick reference
| Elementary charge | Coulomb | Milliampere-hour | Millicoulomb |
|---|---|---|---|
| 1 e | = 1.602176634e-19 C | = 4.45049065e-20 mAh | = 1.602176634e-16 mC |
| 10 e | = 1.602176634e-18 C | = 4.45049065e-19 mAh | = 1.602176634e-15 mC |
| 100 e | = 1.602176634e-17 C | = 4.45049065e-18 mAh | = 1.602176634e-14 mC |
| 1000 e | = 1.602176634e-16 C | = 4.45049065e-17 mAh | = 1.602176634e-13 mC |
Where the elementary charge fits
The next larger electric charge unit is the statcoulomb (statC). 1 e = 4.80320471257026372e-10 statC, and 1 statC ≈ 2081943327 e.
Frequently asked questions
- How many coulombs are in one elementary charge?
- One elementary charge = 1.602176634e-19 C (coulombs).
- How many milliampere-hours are in one elementary charge?
- One elementary charge = 4.45049065e-20 mAh (milliampere-hours).
- How many millicoulombs are in one elementary charge?
- One elementary charge = 1.602176634e-16 mC (millicoulombs).