Science
Point-charge electric field
Calculate the radial electric field of a point charge in vacuum.
Calculators / Science / Coulomb force
Coulomb force calculator
Estimate electrostatic force between two point charges in vacuum.
On this page
Signed radial force1.8N
Force magnitude1.8N
Calculator controls
How to calculate
Estimate electrostatic force between two point charges in vacuum.
Signed radial force = 8.9875517923e9*a*b/1e12/r^2 N; Force magnitude = 8.9875517923e9*abs(a*b)/1e12/r^2 N
Worked example
First charge (µC): 1; Second charge (µC): 2; Charge separation (m): 0.1.
Signed radial force: 1.8 N; Force magnitude: 1.8 N.
Assumptions and limits
Positive signed force means repulsion; negative means attraction. Uses point charges in vacuum, excluding material permittivity, shielding and distributed charges.
Results are rounded for display; calculations use unrounded values. Read our calculation methodology.
Understanding the result
Estimate electrostatic force between two point charges in vacuum.
When this tool is useful
Signed radial force = 8.9875517923e9*a*b/1e12/r^2 N; Force magnitude = 8.9875517923e9*abs(a*b)/1e12/r^2 N
Understanding your inputs
| Input | What to enter |
|---|---|
| First charge (µC) | Enter a number of at least -1000000000000 and no more than 1000000000000. |
| Second charge (µC) | Enter a number of at least -1000000000000 and no more than 1000000000000. |
| Charge separation (m) | Enter a number of at least 1e-12 and no more than 1000000000000. |
Frequently asked questions
What assumptions does this calculation use?
Positive signed force means repulsion; negative means attraction. Uses point charges in vacuum, excluding material permittivity, shielding and distributed charges.
How is the result calculated?
Signed radial force = 8.9875517923e9*a*b/1e12/r^2 N; Force magnitude = 8.9875517923e9*abs(a*b)/1e12/r^2 N