Electric Field Calculator

Electric field, force, and potential from charge and distance.

Source Charge (C)

Distance (m)

Test Charge (C)

Tab to move between fields

Electric Field (V/m)

898,755

Force on Test Charge (N)

Electric Potential (V)89,875.5

Potential Energy (J)0

Direction (1=away, -1=toward)1

Field at 2x Distance (V/m)224,689

How to Use This Calculator

Enter the source charge (C) — use scientific notation, e.g., 1e-6 for 1 microcoulomb.
Enter the distance (m) from the source charge to the point of interest.
Enter the test charge (C) to compute force on it.
Read electric field strength (V/m) and force on the test charge (N).
Review electric potential (V) and potential energy (J) at this distance.

What each input means

Electric Field (V/m): E = kQ/r². Field strength in volts per meter.
Force on Test Charge (N): F = qE. Coulomb force in newtons.
Electric Potential (V): V = kQ/r. Voltage at this distance.
Potential Energy (J): U = qV. Energy of test charge in the field.
Direction (1=away, -1=toward): Field points away from positive, toward negative charges.
Field at 2x Distance (V/m): Field at double the distance (1/4 strength, inverse square law).

Identify Input Parameters
Source Charge (C) = 0.000001, Distance (m) = 0.1, Test Charge (C) = 1e-9 = 3 input(s) provided
Calculate Electric Field
Electric Field = parseFloat(electricField.toPrecision(6))
898755 = 898755
Calculate Force on Test Charge
Force on Test Charge = parseFloat(force.toPrecision(6))
0.000898755 = 0.000898755
Calculate Electric Potential
Electric Potential = parseFloat(potential.toPrecision(6))
89875.5 = 89875.5
Calculate Potential Energy
Potential Energy = parseFloat(potentialEnergy.toPrecision(6))
0.0000898755 = 0.0000898755