Coulomb’s Law Charge Calculator

Calculate force, distance, or charge using Coulomb’s Law and entering known values in the calculator below.

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How to Calculate Electrostatic Force

Using Coulomb’s Law it’s possible to solve the electrostatic force between two charges if the distance between them is known. Coulomb’s Law defines the following formula for this.

The force F is equal to the Coulomb constant ke times the charge of an object q1 times the charge of the other object q2 divided by the distance d squared.

F = keq1q2r2

ke is the Coulomb constant, which is equal to 8,987,551,787.3681764 Nm2C−2.

q1 is the charge of the first object in coulombs.

q2 is the charge of the first object in coulombs.

r is the distance between the objects in meters.

F is the electrostatic force in newtons.

How to Calculate the Distance Between Objects

If the electrostatic charge and force are known, then it’s possible to use Coulomb’s Law to find the distance between the objects.

r = √ (ke × q1 × q2 ÷ F)

So, the distance between objects r is equal to the square root of the Coulomb constant ke times the charge of an object q1 times the charge of the other object q2 divided by the force F.

How to Calculate the Charge of an Object

If the electrostatic charge of one object, the force, and the distance are known, then the following formula can be used to solve the charge of the second object.

q2 = F × r2 ÷ ke ÷ q1

Thus, the charge of an object is equal to the force F times the distance between objects r squared divided by the Coulomb constant ke divided by the charge of the other object q1.