Resistance Calculator

Calculate electrical resistance using Ohm's law (R = V/I) or from resistivity, length, and cross-sectional area.

Enter values to calculate resistance.

Resistance Formulas

R = V / I (Ohm's Law)
R = ρ × L / A (from resistivity)

Common Resistivities

Materialρ (Ω·m)
Copper1.68 × 10⁻⁸
Aluminum2.65 × 10⁻⁸
Gold2.44 × 10⁻⁸
Iron9.71 × 10⁻⁸

Last updated: 2026-08-08