Coulomb Law Calculator
Calculate electric force between two point charges
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Coulomb Law Formula
F = k |q1 q2| / r^2
k = 8.9875517923 x 10^9 N m^2/C^2
Coulomb law describes the force between ideal point charges. Force grows with charge size and decreases with the square of distance.
⚠ This calculator assumes point charges in vacuum or air approximation. Real materials and geometry can change the result.
What Is Coulomb Law?
Coulomb law is the electrostatic force law for charges. It is one of the basic equations behind electric fields and charged particle interactions.
Charge Product
Force is proportional to q1 times q2.
Inverse Square
Doubling distance reduces force to one fourth.
Direction
Same signs repel and opposite signs attract.
Point Charge Model
The formula assumes charges are point-like.
Example: For q1 = 1 microcoulomb, q2 = 2 microcoulombs, and r = 0.5 m, F is about 0.0719 N.
Applications of Coulomb Law
Electrostatics
Electric Fields
Physics Class
Charged Particles
Electronics Fundamentals
Frequently Asked Questions
What is a Coulomb law calculator?▼
It calculates the electrostatic force between two point charges separated by a distance.
What is Coulomb law formula?▼
F = k |q1 q2| / r^2, where k is Coulomb constant and r is distance.
How do I use this electric force calculator?▼
Enter q1, q2 in coulombs and distance in meters. The tool returns force in newtons.
How do I know if force is attractive or repulsive?▼
Charges with the same sign repel; charges with opposite signs attract.
Where is Coulomb law used?▼
It is used in electrostatics, physics classes, electric fields, charged particles, and electronics fundamentals.
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