Conductivity ↔ Resistivity Calculator
Common Materials Reference (at 20 °C)
Click a row to load its value into the converter.
| Material | Conductivity (S/m) | Resistivity (Ω·m) | Type |
|---|---|---|---|
| Silver | 6.30×10⁷ | 1.59×10⁻⁸ | Conductor |
| Copper (annealed) | 5.96×10⁷ | 1.68×10⁻⁸ | Conductor |
| Gold | 4.52×10⁷ | 2.21×10⁻⁸ | Conductor |
| Aluminum | 3.77×10⁷ | 2.65×10⁻⁸ | Conductor |
| Iron | 1.00×10⁷ | 1.00×10⁻⁷ | Conductor |
| Lead | 6.90×10⁶ | 1.45×10⁻⁷ | Conductor |
| Carbon (graphite) | 1.38×10⁶ | 7.25×10⁻⁷ | Conductor |
| Seawater | 5.0 | 0.20 | Electrolyte |
| Drinking water | 5.0×10⁻² | 20 | Electrolyte |
| Silicon (intrinsic) | 1.56×10⁻³ | 6.40×10² | Semiconductor |
| Germanium | 4.35×10⁻⁴ | 2.30×10³ | Semiconductor |
| Glass | 1.0×10⁻¹² | 1.0×10¹² | Insulator |
| PTFE (Teflon) | 1.0×10⁻¹⁶ | 1.0×10¹⁶ | Insulator |
Temperature coefficient note
For metals, resistivity increases with temperature: ρ(T) = ρ₀[1 + α(T − 20 °C)]. Typical α values: copper 0.00393/°C, aluminum 0.00390/°C, silver 0.00380/°C, gold 0.00340/°C. Semiconductors behave oppositely — their conductivity rises as they heat up. The table values above are standardized at 20 °C.
Frequently Asked Questions
How do you convert conductivity to resistivity?
Resistivity is the reciprocal of conductivity: ρ (Ω·m) = 1 / σ (S/m). Copper at 5.96×10⁷ S/m has resistivity ≈ 1.68×10⁻⁸ Ω·m.
What is the formula relating resistivity and conductivity?
ρ = 1/σ and σ = 1/ρ. They are exact mathematical reciprocals of each other.
What is the resistivity of copper in ohm meters?
About 1.68×10⁻⁸ Ω·m at 20 °C (conductivity ≈ 5.96×10⁷ S/m, the 100% IACS reference).
What units are used for conductivity and resistivity?
Conductivity: siemens per meter (S/m), often MS/m or % IACS. Resistivity: ohm·meters (Ω·m), sometimes μΩ·cm for metals.
How does temperature affect resistivity?
In metals resistivity rises with temperature: ρ(T) = ρ₀[1 + α(T − T₀)]. In semiconductors, conductivity rises with temperature instead.
Which metal has the highest electrical conductivity?
Silver (≈ 6.30×10⁷ S/m), followed by copper. Copper dominates wiring because it is far cheaper.
What is the conductivity of aluminum vs copper?
Aluminum ≈ 3.77×10⁷ S/m, about 61% IACS — lighter than copper, widely used in overhead lines.
What is the difference between conductance and conductivity?
Conductivity (S/m) is a material property; conductance (siemens) describes a specific object: G = σA/L.
What does 100% IACS mean?
The International Annealed Copper Standard: 5.96×10⁷ S/m (1.68×10⁻⁸ Ω·m) at 20 °C. Other metals are rated as a percentage of it.
How do you convert S/m to ohm meter?
Take the reciprocal: ρ (Ω·m) = 1 / σ (S/m). 10⁶ S/m = 10⁻⁶ Ω·m.
Why is seawater conductive?
Dissolved ions (Na⁺, Cl⁻) carry charge — about 5 S/m, ten million times less than copper but significant for marine systems.
What is the resistivity of silicon?
Intrinsic silicon ≈ 6.4×10² Ω·m, but doping can shift it across many orders of magnitude.
Is resistivity the inverse of conductivity?
Yes — ρ = 1/σ exactly.
What is a good conductor vs a good insulator?
Conductors like copper sit near 10⁻⁸ Ω·m; insulators like PTFE exceed 10¹⁶ Ω·m — over 20 orders of magnitude apart.
How do I measure resistivity in practice?
Use the four-point probe method to eliminate contact resistance, then convert sheet resistance with sample thickness.
Does AC frequency change effective resistivity?
Material resistivity doesn't change, but the skin effect raises effective AC resistance at high frequencies.
Related searches: conductivity to resistivity conversion, S/m to ohm meter calculator, resistivity formula ρ = 1/σ, copper resistivity ohm meter, aluminum conductivity S/m, silver conductivity siemens per meter, % IACS conductivity chart, temperature coefficient of resistivity, semiconductor resistivity silicon, insulator resistivity table, four point probe resistivity, skin effect AC resistance, electrical conductivity units converter, ohm meter to siemens per meter, metal resistivity comparison, resistivity of seawater, conductivity of drinking water, micro ohm cm to ohm meter, resistivity vs temperature formula.