Resistance of a Wire (R = ρL/A)
Also known as R = rho L / A · conductor resistance
Enter your known values, leave one input blank, and solves for the missing one. Try different units for next level excitement!
Learning zone
Resistance behaves like traffic: double the road length and congestion doubles; double the lanes (area) and it halves. The material's own contribution is its resistivity — copper's 1.68 × 10⁻⁸ Ω·m is why it wires the world. A hundred meters of 2.5 mm² copper cable comes to 0.67 Ω, enough to drop a couple of volts at high current, which is why long runs demand thicker wire and why power lines transmit at high voltage to keep I (and I²R loss) small.
Resistance of a Wire (R = ρL/A)
Where
- = Resistance
- = Resistivity
- = Wire length
- = Cross-sectional area
Missing one of these? Work it out first, then come back
- Resistance — Ohm's Law, Electrical Power (P = I²R)
- Resistivity — Water Resistivity and Conductivity, Voltage Drop, Single Phase
- Wire length — Force Between Parallel Wires, Magnetic Force on a Current-Carrying Wire
- Cross-sectional area — Volumetric Flow Rate (Q = Av), Heat Conduction Rate