Charge comes in whole numbers of the elementary charge. A balloon rubbed on your hair might carry a few nanocoulombs – billions of extra electrons, still a vanishingly small fraction of all its electrons.
How to use the Excess Electrons Calculator
- Net charge Q
Results update as you type, every field has its own unit menu, and everything is calculated in your browser.
How it works
Enter the net charge with its sign.
What each result means
- Number of electrons = abs([Net charge Q])÷1.602176634e-19
- In moles = abs([Net charge Q])÷1.602176634e-19÷6.02214076e+23
Example values
How the main result changes when Net charge Q changes and everything else stays at the example values above:
| Net charge Q (nC) | Number of electrons |
|---|---|
| -2.5 | 15,603,772,686.1519 |
| -3.75 | 23,405,659,029.2279 |
| -5 | 31,207,545,372.3038 |
| -6.25 | 39,009,431,715.3798 |
| -7.5 | 46,811,318,058.4557 |
| -10 | 62,415,090,744.6076 |
Formula
N = |Q| / e, e = 1.602176634 × 10⁻¹⁹ C
Worked example
Inputs — Net charge Q: -5 nC.
Results — Number of electrons = 31,207,545,372.303814; Electrons are = In excess (negative charge); In moles = 5.1821e-14 mol.
Key terms
- Elementary charge
- e, the charge of a proton.
Frequently asked questions
Why is the charge quantised?
Charge comes in multiples of e (quarks are confined inside hadrons).
How many electrons in 1 C?
About 6.24 × 10¹⁸.
Does a positive object have extra protons?
No – it is missing electrons.
How much charge does static electricity involve?
Typically nanocoulombs to microcoulombs.