Resistivity Calculator
⚡ Electricity & magnetism. Use the Resistivity formula to find resistance, resistivity ρ, length, cross-section area: pick the value you want, type the others, and the answer updates as you go.
Pick the ○ next to the value you want to find, fill in the others, and it solves as you type.
What each letter means
| Quantity | Unit |
|---|---|
| Resistance | Ω |
| Resistivity ρ | Ω m |
| Length | m |
| Cross-section area | m² |
Worked example
Find the resistance when Resistivity ρ = 1.72 × 10⁻⁸ Ω m, Length = 50 m, Cross-section area = 1 × 10⁻⁶ m².
Using R = (ρ L)/A: Resistance = 0.86 Ω.
Frequently asked questions
What is the formula for Resistivity?
R = (ρ L)/A.
What do the letters stand for, and what units are used?
Resistance in Ω, Resistivity ρ in Ω m, Length in m, Cross-section area in m².
How do you calculate resistance?
Put the values into R = (ρ L)/A. For example, with Resistivity ρ = 1.72 × 10⁻⁸ Ω m, Length = 50 m, Cross-section area = 1 × 10⁻⁶ m², resistance = 0.86 Ω.
Can I solve for a different value?
Yes. In the calculator above, pick the circle next to any value (resistance, resistivity ρ, length, cross-section area) and fill in the others: it rearranges the formula for you.
