Calculator Inputs
The page stays in a single-column layout, while the input controls use three columns on large screens, two on smaller screens, and one on mobile.
Formula Used
Here, ρ is resistivity, σ is conductivity, R is resistance, G is conductance, L is conductor length, A is cross-sectional area, α is the temperature coefficient, T₀ is the reference temperature, and T is the operating temperature.
How to Use This Calculator
- Select whether the known input is resistivity or conductivity.
- Enter the known value and choose the matching unit.
- Add length and cross-sectional area if you want resistance and conductance results.
- Enter reference temperature, operating temperature, and the temperature coefficient.
- Optionally add voltage and current to estimate power, electric field, current density, and measured resistance.
- Press the calculate button. The result appears below the header and above the form, with export buttons and a Plotly graph.
Example Data Table
| Material | Resistivity at 20 °C (Ω·m) | Conductivity at 20 °C (S/m) | Typical α (/°C) |
|---|---|---|---|
| Copper | 1.68e-8 | 5.95e7 | 0.0039 |
| Aluminum | 2.82e-8 | 3.55e7 | 0.0043 |
| Iron | 9.71e-8 | 1.03e7 | 0.0050 |
| Nichrome | 1.10e-6 | 9.09e5 | 0.0004 |
These are typical reference values for demonstration. Real materials vary with purity, alloy content, strain, and measurement method.
FAQs
1) What is the difference between resistivity and resistance?
Resistivity is a material property. Resistance depends on both material and geometry. Two copper wires share the same resistivity, but a longer or thinner wire has higher resistance.
2) Why does conductivity usually decrease as metal temperature rises?
For most metals, hotter temperatures increase lattice vibration, so electrons scatter more. That raises resistivity and lowers conductivity. Materials with negative temperature coefficients can behave differently.
3) Can I enter area in mm² instead of m²?
Yes. Enter the number and choose the matching area unit. The calculator converts everything to SI internally before solving, which keeps resistance and conductivity results consistent.
4) What does the temperature coefficient mean?
The temperature coefficient estimates how strongly resistivity changes per degree relative to a reference temperature. Use published values for the specific material and reference temperature whenever possible.
5) Why does a longer conductor have more resistance?
It means charge carriers have more path to travel, so the conductor offers more opposition. In the equation R = ρL/A, resistance rises directly with length.
6) Can this calculator be used for semiconductors or liquids?
Yes, as an estimate. For liquids, soils, semiconductors, and composites, temperature behavior can be non-linear, so laboratory data may be better than a single coefficient.
7) What happens if I only know resistivity or conductivity?
You still get reciprocal conversion between resistivity and conductivity. Geometry-based resistance, conductance, and field quantities appear only when you also supply length, area, or electrical measurements.
8) Why do measured and theoretical results differ?
Check units first, especially area units and micro or milli prefixes. Then compare temperature assumptions, contact resistance, impurities, and measurement uncertainty.