Coulomb's Law

Calculate the electrostatic force and potential energy between two point charges, free online.

Charge 1 (µC)

Charge 2 (µC)

Distance (m)

Relative permittivity εr

About this calculator

Coulomb's law gives the force F = k·q₁q₂ ÷ (ε_r·r²) with k = 8.9875×10⁹ N·m²/C². Like charges repel and opposite charges attract. The potential energy is U = k·q₁q₂ ÷ (ε_r·r).