Mathematics · Mathematical Physics
Coulomb Electric Force Calculator
Calculate the signed electrostatic force magnitude between two point charges.
Inputs and results stay in this browser. Change one value at a time to explore the relationship.
Calculation steps
- Convert charges: 2 μC=0.000002 C; -3 μC=-0.000003 C.
- Charge product=-6e-12; distance squared=0.25.
- Force=8987551792.3×-6e-12÷0.25=-0.21570124301519997 N (attractive).
Problem → model → reason → result
What problem does this model solve?
Calculate the signed electrostatic force magnitude between two point charges.
Why does the model apply?
Electric force follows an inverse-square law; the charge-product sign distinguishes repulsion from attraction.
What assumptions does it make?
Values use the displayed units, the named classical model describes the system, and idealisations such as constant acceleration, point particles or negligible drag apply where stated.
Formula
F=kq₁q₂/r²
Calculation and working
The calculator above substitutes your inputs into the model and leaves the calculation steps visible so the answer can be checked rather than merely accepted.
What does the result mean?
The result answers the stated problem in the units implied by your inputs. Read its sign, size and units together, then compare it with the original values before drawing a conclusion.
Worked example
Charges +2 μC and −3 μC separated by 0.5 m exert about −0.216 N, indicating attraction.
Common mistake
This calculator expects charge in microcoulombs and converts it to coulombs internally.
When does this model not apply?
Ideal classical models omit effects such as drag, relativity, extended-body geometry, material response and measurement uncertainty unless explicitly included.
How to learn with this calculator
Begin with the worked example, then change one value while keeping the others fixed. Compare the new result and calculation steps to identify which part of the formula changed.
Clear answers
Frequently asked questions
What does the Coulomb force do?
Calculate the signed electrostatic force magnitude between two point charges.
How does the Coulomb force work?
The calculator applies F=kq₁q₂/r². Electric force follows an inverse-square law; the charge-product sign distinguishes repulsion from attraction.
What can I learn from the Coulomb force?
It connects the mathematical rule to your chosen numbers and shows each calculation step. Change one input at a time to see how the result responds.
Does MW SysArc receive or store what I enter?
No. The calculation runs locally in your browser. MW SysArc does not receive or store your calculation inputs.
How should I use the result?
Use the steps to understand the method, then verify important school or professional work using the notation and rounding rules required in your setting.
Last reviewed 2026-07-14. Calculations tested 2026-07-14.