Electric Field Calculator
Calculate point-charge fields, electric forces, potential and ideal uniform fields locally. Local educational electrostatics model in vacuum. No materials, fringe fields, relativistic motion or electrical safety assessment.
A QUICK WALKTHROUGH
How to use this tool
- Choose a calculation mode and units.
- Enter signed charges or a signed field/potential drop, with a positive distance.
- Calculate and interpret the signs using the stated convention.
Equations and constants
Eᵣ = kQ/r²; |E| = k|Q|/r²; F = Eq; Fᵣ = kQq/r²; V = kQ/r; Uₑ = −eV; E = V/d; Fₑ = −eE; aₑ = Fₑ/mₑ. k = 8.9875517923 × 10⁹ N·m²/C²; e = 1.602176634 × 10⁻¹⁹ C; mₑ = 9.1093837139 × 10⁻³¹ kg.
Field direction
Point-charge signs use the outward radial direction as positive. For E·q and uniform fields, positive is your chosen axis; V is the signed potential drop along it. Potential is zero at infinity; electron charge is −e.
GOOD TO KNOW
Common questions
Does this upload my input?
No. All calculations run in your browser. These ideal textbook results are not equipment design or safety advice.