Coulomb's Law Calculator
Calculate the electrostatic force between two point charges.
This tool is for informational and educational purposes only. It is not a substitute for professional financial, medical, legal, or engineering advice. See Terms of Service.
Can't find what you need?
Request a ToolHow to Use the Coulomb's Law Calculator
Enter the two charge values in coulombs and the distance between them in meters. The calculator instantly computes the electrostatic force using Coulomb's law. Use scientific notation for small charges (e.g., 1e-6 for one microcoulomb).
About Coulomb's Law
Coulomb's law, discovered by Charles-Augustin de Coulomb in 1785, describes the force between two stationary electric charges. The force is proportional to the product of the charges and inversely proportional to the square of their separation distance. This inverse-square law has the same mathematical form as Newton's law of gravitation. Coulomb's law is the foundation of electrostatics and is essential for understanding electric fields, capacitors, and molecular bonding.
Frequently Asked Questions
What is Coulomb's law?
Coulomb's law describes the electrostatic force between two point charges. The force is proportional to the product of the charges and inversely proportional to the square of the distance between them.
Is the force attractive or repulsive?
Like charges (both positive or both negative) repel each other. Opposite charges attract. The sign of the force indicates direction.
What is the value of Coulomb's constant?
Coulomb's constant k is approximately 8.99 x 10^9 N m2/C2. It is also written as 1/(4 x pi x epsilon_0) where epsilon_0 is the permittivity of free space.