What is the formula used?

The tool uses R = ρL/A, where R is resistance (Ω), ρ (rho) is resistivity (Ω·m), L is length (m), and A is cross-sectional area (m²). Rearranged: ρ = RA/L, L = RA/ρ, A = ρL/R.

What units does this calculator use?

SI base units by default: Ω for resistance, Ω·m for resistivity, meters for length, and m² for area. The dropdowns let you enter mm, cm, mm², cm², μΩ·m, etc. and results are displayed in the most readable SI prefix.

What are typical resistivity values?

Copper: 1.68×10⁻⁸ Ω·m; Aluminum: 2.82×10⁻⁸ Ω·m; Gold: 2.44×10⁻⁸ Ω·m; Silver: 1.59×10⁻⁸ Ω·m; Iron: 1.0×10⁻⁷ Ω·m; Nichrome: 1.10×10⁻⁶ Ω·m. These are at 20 °C.

Does temperature affect resistivity?

Yes — resistivity increases with temperature for most metals. The preset values are at 20 °C. For precision work, apply the temperature coefficient: ρ(T) = ρ₀[1 + α(T − T₀)].

What is the difference between resistivity and resistance?

Resistivity (ρ) is an intrinsic material property independent of shape. Resistance (R) depends on both the material and the geometry (length and cross-section) of the conductor.

Resistivity Calculator

Name: Resistivity Calculator
Availability: InStock
Author: Nham Vu

Solve for any variable in R = ρL/A — resistance, resistivity, length, or cross-sectional area.