Electric Field Calculator Formula

Understand the math behind the electric field calculator. Each variable explained with a worked example.

Formulas Used

Electric Field Strength

electric_field = 8.9875e9 * abs(charge) / pow(distance, 2)

Variables

VariableDescriptionDefault
chargeCharge(C)0.000001
distanceDistance from Charge(m)0.1

How It Works

Electric Field

The electric field describes the force per unit charge experienced by a test charge placed near a source charge.

Formula

E = k * |Q| / r²

where k = 8.9875 x 10^9 N·m²/C² is Coulomb's constant. The field points radially outward from positive charges and inward toward negative charges.

Worked Example

Electric field 10 cm from a 1 microcoulomb charge.

charge = 0.000001distance = 0.1
  1. 01E = k * Q / r²
  2. 02E = 8.9875e9 * 1e-6 / 0.01
  3. 03E = 8987.5 / 0.01
  4. 04E = 898,750 N/C

Ready to run the numbers?

Open Electric Field Calculator