Electric potential is the potential energy per unit charge at a point. Unlike the electric field, it is a scalar – potentials from several charges simply add up, with signs.
How to use the Electric Potential Calculator
- Configuration
- Relative permittivity ε_r
- Charge q₁
- Distance r₁
- Charge q2
- Distance r2
- Charge q3
- Distance r3
- Charge q4
- Distance r4
- Charge q5
- Distance r5
Results update as you type, every field has its own unit menu, and everything is calculated in your browser.
How it works
Choose single charge or system and enter each charge (with sign) and its distance from the point.
Inputs explained
| Field | What to enter |
|---|---|
| Configuration | Choose one: Single point charge, System of point charges |
| Relative permittivity ε_r | A number |
| Charge q₁ | Units: nC, µC, C, pC, e |
| Distance r₁ | Units: cm, mm, m, in, ft |
| Charge q2 | Units: nC, µC, C, pC, e |
| Distance r2 | Units: cm, mm, m, in, ft |
| Charge q3 | Units: nC, µC, C, pC, e |
| Distance r3 | Units: cm, mm, m, in, ft |
| Charge q4 | Units: nC, µC, C, pC, e |
| Distance r4 | Units: cm, mm, m, in, ft |
| Charge q5 | Units: nC, µC, C, pC, e |
| Distance r5 | Units: cm, mm, m, in, ft |
Example values
How the main result changes when Relative permittivity ε_r changes and everything else stays at the example values above:
| Relative permittivity ε_r | Electric potential V (V) |
|---|---|
| 1 | 179.751 |
| 1.25 | 143.8008 |
| 1.5 | 119.834 |
| 2 | 89.8755 |
Formula
V = k·q / (ε_r·r), V_total = Σ k·qᵢ/(ε_r·rᵢ)
Worked example
Inputs — Configuration: Single point charge; Relative permittivity ε_r: 1; Charge q₁: 2 nC; Distance r₁: 10 cm.
Results — Electric potential V = 179.751036 V; Energy of a +1 µC test charge there = 0.17975 mJ.
Key terms
- Electric potential
- Potential energy per unit charge.
Frequently asked questions
Is potential a vector?
No – it is a scalar, so contributions add algebraically.
Where is the potential zero?
By convention, infinitely far away.
What is the relation to the field?
The field is the negative gradient of potential.
How is potential related to voltage?
Voltage is the difference in potential between two points.