Coulomb's law calculator

Coulomb's law explains the electrostatic law between two point charges placed at a difference. According to this law,

What is Coulomb's Law?

The force of attraction or repulsion between the charges is directly proportional to the product of their charges and inversely proportional to the square of the difference between them.

The force can be attractive or repulsive according to the charges they are either the same or different. This law helps you estimate the magnitude of the intensity of the force between the charges.

Coulomb's law calculator Example

For a better understanding, we have a solved example of Coulomb’s law as follow:

What is the intensity of the force between two charges having a magnitude of 5 C which are 10 meters apart? By putting values in the formula, we get

F = 9.0 x 109 * 5 * 5 / (10 * 10)
F = 2.25 * 109 N

This is simply placing the values and calculating them from your calculator

Mathematical Representations

You can demonstrate Coulomb’s Law in the form of symbols as represented below:

\[F = K\left( {\frac{{{q_1} \times {q_2}}}{{{r^2}}}} \right)\]


  • F is the electrostatic force of attraction or repulsion
  • q1 is the intensity of 1st point charge
  • q2 is the intensity of 2nd point charge
  • r the distance between both of them
  • K is Coulomb’s constant

We have converted the sign of proportionality into the sign of equality therefore, we need to put the constant here.

The value for Ke remains the same throughout, you do not have to remember it. It is always 8.98755*10^9 N*m^2/C^2. If we see mathematically, the value for k is as follow:

Unit of Coulombs Law:

As this law gives you the value of, therefore the units will be Newton.

Calculator use

What will be the benefit of using this calculator? You do not have to mess with complicated values. Moreover, the trouble of putting the values for ke will no more exist using this calculator. You simply have to put the magnitude and the distance between the charges and the force of attraction or repulsion will pop up on your screen without any complicated solution. So stop messing with the values and put them here for results.