Enter your Charge, Distance, and Medium into the Electric Field Calculator to find the Electric Field Strength at any point in space, along with the Electric Field (V/m), Power Density, and Field Intensity.
Electric Field Strength
--
Electric Field (V/m)
--
Power Density
--
Field Intensity
--
An electric field is a physical field that surrounds electric charges and exerts force on other charges within the field. It represents the force per unit charge that would be experienced by a small test charge placed at any point in space.
The electric field of a point charge is calculated using E = kQ/r², where k is Coulomb's constant (8.99 × 10⁹ N·m²/C²), Q is the charge in Coulombs, and r is the distance from the charge in meters.
Electric field intensity is a vector quantity. It has both magnitude and direction. The direction of the electric field is the direction of the force that would be exerted on a positive test charge.
The SI unit of electric field is Newton per Coulomb (N/C) or equivalently Volt per meter (V/m). Both units represent the same physical quantity: force per unit charge.
For a point charge, the electric field strength decreases with the square of the distance (inverse square law). If you double the distance, the field strength becomes one-fourth as strong.
Power density is the amount of electromagnetic power per unit area, measured in watts per square meter (W/m²). It's calculated from the electric field strength and represents the intensity of electromagnetic radiation.
Different media have different permittivity values, which affect the electric field strength. In materials with higher permittivity (like water), the electric field is reduced compared to vacuum or air.
Coulomb's constant (k = 8.99 × 10⁹ N·m²/C²) appears in electric field and force calculations. It relates to the permittivity of free space and determines the strength of electrostatic interactions in vacuum.