Wire Resistance Calculator

Calculate electrical resistance and conductance of wires using Pouillet's Law

Wire Resistance Calculator

Total length of the wire

Diameter of the wire

Material affects resistivity and temperature coefficient

Operating temperature (affects resistivity)

Electrical Properties

Wire Resistance (R)

53.476 mΩ
Total resistance

Wire Conductance (G)

18.700 S
G = 1/R
3.142 mm²
Cross-sectional Area
5.348 mΩ
Resistance per Meter
1.68e-8 Ω⋅m
Material Resistivity
Voltage Drop (1A)
0.053476 V
V = I × R
Power Loss (1A)
0.053476 W
P = I² × R

Formula: R = ρ × L / A

Where: ρ = 1.68e-8 Ω⋅m, L = 10.000 m, A = 3.142 mm²

Temperature correction: ρ(T) = ρ₀[1 + α(T - T₀)]

Resistance Analysis

ℹ️ Low resistance - good conductor, suitable for power transmission

Example Calculation - Copper Wire

Given Parameters

Material: Copper

Length: 100 meters

Diameter: 2.5 mm

Temperature: 20°C

Copper Resistivity: 1.68 × 10⁻⁸ Ω⋅m

Calculation Steps

Step 1: Area = π × (d/2)² = π × (0.00125)² = 4.91 × 10⁻⁶ m²

Step 2: R = ρ × L / A

Step 3: R = 1.68×10⁻⁸ × 100 / 4.91×10⁻⁶

Result: R = 0.342 Ω

Conductance: G = 1/R = 2.924 S

Material Resistivities (20°C)

Silver1.59×10⁻⁸ Ω⋅m
Copper1.68×10⁻⁸ Ω⋅m
Gold2.44×10⁻⁸ Ω⋅m
Aluminum2.65×10⁻⁸ Ω⋅m
Iron9.71×10⁻⁸ Ω⋅m
Nichrome1.10×10⁻⁶ Ω⋅m

Factors Affecting Resistance

📏

Length: Resistance increases with length

Area: Resistance decreases with larger cross-section

🔬

Material: Different materials have different resistivities

🌡️

Temperature: Most materials show increased resistance with temperature

Understanding Wire Resistance

Pouillet's Law (Resistance Formula)

The resistance of a wire is calculated using Pouillet's Law, which relates resistance to the physical properties of the conductor and its geometry.

Main Formula

R = ρ × L / A

  • R: Resistance (Ω)
  • ρ: Resistivity (Ω⋅m)
  • L: Length (m)
  • A: Cross-sectional area (m²)

Temperature Effects

Resistivity changes with temperature for most materials. The temperature-adjusted resistivity is calculated using the temperature coefficient.

Temperature Formula

ρ(T) = ρ₀[1 + α(T - T₀)]

  • ρ(T): Resistivity at temperature T
  • ρ₀: Resistivity at reference temperature
  • α: Temperature coefficient
  • T₀: Reference temperature (20°C)

Conductance and Resistivity

Conductance Formula

G = σ × A / L = 1 / R

Conductance (G) is the inverse of resistance and measures how easily current flows through the wire.

Resistivity vs Conductivity

σ = 1 / ρ

Conductivity (σ) is the inverse of resistivity (ρ) and represents the material's ability to conduct electricity.