Coulomb's Law Calculator

Calculate the electrostatic force between two point charges.

1. Particles & Distance
Charge 1 (q₁) C
Use 1e-6 for μC
Charge 2 (q₂) C
Positive or Negative
Distance (r) m
2. Constant (k)
Coulomb Constant
Electrostatic Force (F)
0.00
Newtons (N)
Attraction Force Interaction
Force Visualizer
q₁
q₂

What is Coulomb's Law?

Coulomb's Law is a law of physics that describes the interaction between electrically charged objects. It states that the magnitude of the electrostatic force of attraction or repulsion between two point charges is directly proportional to the product of the magnitudes of charges and inversely proportional to the square of the distance between them.

The Equation:

F = k · (|q₁| · |q₂|) / r²

  • F: Electrostatic force (Newtons)
  • k: Coulomb's constant (≈ 8.99 × 10⁹ N·m²/C²)
  • q₁, q₂: Signed magnitudes of the charges (Coulombs)
  • r: Distance between charges (Meters)

Key Insight: If the charges have the same sign, the force is repulsive (they push away). If the charges have opposite signs, the force is attractive (they pull together).