Wire Resistance Calculator
An interactive tool to calculate and understand the principles of electrical resistance in wires.
Resistance Calculator
Calculated Resistance (R)
Based on: R = ρ * (L / A)
Understanding Material Resistivity (ρ)
Resistivity is a fundamental property that quantifies how strongly a given material opposes the flow of electric current. A low resistivity indicates a material that readily allows the flow of current (a conductor). The chart below compares the resistivity of common materials at 20°C. Click a bar to select that material in the calculator.
How Length (L) & Area (A) Affect Resistance
The physical shape of a wire plays a crucial role in its resistance. Longer wires provide more path for resistance to build up, while wider wires (larger cross-sectional area) offer more pathways for current, reducing resistance. Use the sliders below to see this relationship in action.
Resistance: Ω
American Wire Gauge (AWG) Chart
AWG is a standard for wire sizes. A lower gauge number means a thicker wire with lower resistance. Click any row in the table to load its diameter into the calculator above.
| AWG | Diameter (mm) | Area (mm²) |
|---|
