Coulomb's Law Force Calculator

Summary

Enter two charges and the distance between them to compute the electrostatic force using Coulomb's Law.

How it works

1. Enter the magnitude of the first charge (q1) and select its unit.
2. Enter the magnitude of the second charge (q2) and select its unit.
3. Enter the separation distance (r) between the charges and select its unit.
4. The electrostatic force is computed instantly using F = k·q1·q2/r².
5. Positive force = repulsion (same-sign charges); negative = attraction (opposite-sign charges).
6. Use the reset button to clear all fields and start over.

Use cases

• Calculate forces in introductory physics and electrostatics problems.
• Verify hand-calculated results for homework or exams.
• Explore how force changes with distance (inverse-square law).
• Compare electrostatic vs. gravitational force magnitudes.
• Design ion-trap or capacitor geometry in engineering coursework.
• Understand charge interactions in chemistry (ionic bonding).

Frequently Asked Questions