Electric Resistivity Converters | Ohm-Meters, Ohm-cm & µΩ·m Hub
Ohm-Meters & Ohm-Centimeters
Ohm-Meters & Microohm-Meters
Ohm-Centimeters & Microohm-Meters
What is Electric Resistivity?
Electric Resistivity (commonly denoted by the Greek letter ρ, rho) is a fundamental, intrinsic material property that quantifies how strongly a substance opposes the flow of electric current. Unlike resistance (R), which depends on both the material and its physical geometry (length, width, cross-sectional area), resistivity is an inherent physical constant of the material itself at a given temperature.
According to Pouillet’s Law, the electrical resistance of a uniform conductor is directly proportional to its length and inversely proportional to its cross-sectional area:
R = ρ × (L ÷ A) ⟺ ρ = R × (A ÷ L)
- R: Electrical resistance of the conductor in ohms (Ω).
- A: Cross-sectional area through which current flows (m² or cm²).
- L: Length of the conductor along the direction of current flow (m or cm).
- ρ: Electrical resistivity in Ohm-meters (Ω·m) or Ohm-centimeters (Ω·cm).
- Reciprocal Relationship: Resistivity is the exact mathematical inverse of electrical conductivity (
σ):ρ = 1 ÷ σ.
Material Resistivity Reference Spectrum (at 20 °C)
Electrical resistivity spans over 30 orders of magnitude across nature, from superconductors to pristine dielectric insulators:
| Material Classification | Example Substance | Resistivity in Ω·m | Resistivity in Ω·cm | Resistivity in μΩ·m |
|---|---|---|---|---|
| Superconductor (T < Tc) | YBCO / Niobium-Titanium | 0 Ω·m | 0 Ω·cm | 0 μΩ·m |
| Top Metal Conductor | Silver (Ag) | 1.59 × 10⁻⁸ Ω·m | 1.59 × 10⁻⁶ Ω·cm | 0.0159 μΩ·m |
| Standard Electrical Copper | Copper (Annealed, 100% IACS) | 1.72 × 10⁻⁸ Ω·m | 1.72 × 10⁻⁶ Ω·cm | 0.0172 μΩ·m |
| Corrosion-Resistant Contact | Gold (Au) | 2.44 × 10⁻⁸ Ω·m | 2.44 × 10⁻⁶ Ω·cm | 0.0244 μΩ·m |
| Overhead Transmission Line | Aluminum (Al) | 2.65 × 10⁻⁸ Ω·m | 2.65 × 10⁻⁶ Ω·cm | 0.0265 μΩ·m |
| Heating Element Alloy | Nichrome (80/20 Ni-Cr) | 1.10 × 10⁻⁶ Ω·m | 1.10 × 10⁻⁴ Ω·cm | 1.10 μΩ·m |
| Geological / Marine Water | Seawater (3.5% salinity) | 0.20 Ω·m | 20.0 Ω·cm | 200,000 μΩ·m |
| Semiconductor Wafer (Intrinsic) | Silicon (Si, pure crystalline) | 2.30 × 10³ Ω·m | 2.30 × 10⁵ Ω·cm | 2.30 × 10⁹ μΩ·m |
| Ultra-Pure Semiconductor Water | Deionized Water (18.2 MΩ·cm) | 1.82 × 10⁵ Ω·m | 1.82 × 10⁷ Ω·cm | 1.82 × 10¹¹ μΩ·m |
| Extreme Dielectric Insulator | Teflon (PTFE) / Fused Quartz | 10¹⁶ – 10²⁴ Ω·m | 10¹⁸ – 10²⁶ Ω·cm | 10²² – 10³⁰ μΩ·m |
Resistivity Conversion Formulas
Quick mathematical references for converting between international and laboratory units of electric resistivity:
- Ohm-meters to Ohm-centimeters:
Ω·cm = Ω·m × 100 - Ohm-centimeters to Ohm-meters:
Ω·m = Ω·cm ÷ 100 - Ohm-meters to Microohm-meters:
μΩ·m = Ω·m × 1,000,000 - Microohm-meters to Ohm-meters:
Ω·m = μΩ·m ÷ 1,000,000 - Ohm-centimeters to Microohm-meters:
μΩ·m = Ω·cm × 10,000 - Microohm-meters to Ohm-centimeters:
Ω·cm = μΩ·m ÷ 10,000
Frequently Asked Questions
Why is resistivity measured in Ohm-meters instead of Ohms per meter?
This is one of the most common misunderstandings in electrical engineering. In Pouillet’s Law, ρ = R × (A ÷ L). The units are ohms × (meters² ÷ meters) = ohms × meters = Ω·m. Ohms per meter (Ω/m) measures linear resistance (resistance per unit length of a wire), whereas Ohm-meters (Ω·m) measures bulk material resistivity regardless of wire diameter.
How does temperature affect resistivity?
In pure metallic conductors (like copper and aluminum), resistivity increases linearly with rising temperature due to increased electron-phonon scattering: ρ(T) = ρ₀[1 + α(T - T₀)], where α is the positive temperature coefficient. In contrast, semiconductors and carbon exhibit a negative temperature coefficient (NTC), where resistivity drops dramatically as temperature increases due to thermal generation of charge carriers.
Electric Resistivity Converter (Ohm-Meters to Ohm-Centimeters)
Welcome to ConverterHub’s complete Electric Resistivity Converters directory. Convert seamlessly across electrical materials science, semiconductor engineering, geophysical survey, and metallurgy measurement units—including Ohm-meters (Ω·m), Ohm-centimeters (Ω·cm), and Microohm-meters (μΩ·m)—with exact bulk resistivity formulas, Pouillet’s Law derivations, temperature coefficients (α), and authoritative reference tables spanning superconductors to ultra-pure insulators.
All Electric Resistivity Conversion Tools
Select any electric resistivity conversion tool below for instant calculations, step-by-step mathematical derivations, and technical engineering reference tables:
Ohm-Meters & Ohm-Centimeters
Ohm-Meters & Microohm-Meters
Ohm-Centimeters & Microohm-Meters
What is Electric Resistivity?
Electric Resistivity (commonly denoted by the Greek letter ρ, rho) is a fundamental, intrinsic material property that quantifies how strongly a substance opposes the flow of electric current. Unlike resistance (R), which depends on both the material and its physical geometry (length, width, cross-sectional area), resistivity is an inherent physical constant of the material itself at a given temperature.
According to Pouillet’s Law, the electrical resistance of a uniform conductor is directly proportional to its length and inversely proportional to its cross-sectional area:
R = ρ × (L ÷ A) ⟺ ρ = R × (A ÷ L)
- R: Electrical resistance of the conductor in ohms (Ω).
- A: Cross-sectional area through which current flows (m² or cm²).
- L: Length of the conductor along the direction of current flow (m or cm).
- ρ: Electrical resistivity in Ohm-meters (Ω·m) or Ohm-centimeters (Ω·cm).
- Reciprocal Relationship: Resistivity is the exact mathematical inverse of electrical conductivity (
σ):ρ = 1 ÷ σ.
Material Resistivity Reference Spectrum (at 20 °C)
Electrical resistivity spans over 30 orders of magnitude across nature, from superconductors to pristine dielectric insulators:
| Material Classification | Example Substance | Resistivity in Ω·m | Resistivity in Ω·cm | Resistivity in μΩ·m |
|---|---|---|---|---|
| Superconductor (T < Tc) | YBCO / Niobium-Titanium | 0 Ω·m | 0 Ω·cm | 0 μΩ·m |
| Top Metal Conductor | Silver (Ag) | 1.59 × 10⁻⁸ Ω·m | 1.59 × 10⁻⁶ Ω·cm | 0.0159 μΩ·m |
| Standard Electrical Copper | Copper (Annealed, 100% IACS) | 1.72 × 10⁻⁸ Ω·m | 1.72 × 10⁻⁶ Ω·cm | 0.0172 μΩ·m |
| Corrosion-Resistant Contact | Gold (Au) | 2.44 × 10⁻⁸ Ω·m | 2.44 × 10⁻⁶ Ω·cm | 0.0244 μΩ·m |
| Overhead Transmission Line | Aluminum (Al) | 2.65 × 10⁻⁸ Ω·m | 2.65 × 10⁻⁶ Ω·cm | 0.0265 μΩ·m |
| Heating Element Alloy | Nichrome (80/20 Ni-Cr) | 1.10 × 10⁻⁶ Ω·m | 1.10 × 10⁻⁴ Ω·cm | 1.10 μΩ·m |
| Geological / Marine Water | Seawater (3.5% salinity) | 0.20 Ω·m | 20.0 Ω·cm | 200,000 μΩ·m |
| Semiconductor Wafer (Intrinsic) | Silicon (Si, pure crystalline) | 2.30 × 10³ Ω·m | 2.30 × 10⁵ Ω·cm | 2.30 × 10⁹ μΩ·m |
| Ultra-Pure Semiconductor Water | Deionized Water (18.2 MΩ·cm) | 1.82 × 10⁵ Ω·m | 1.82 × 10⁷ Ω·cm | 1.82 × 10¹¹ μΩ·m |
| Extreme Dielectric Insulator | Teflon (PTFE) / Fused Quartz | 10¹⁶ – 10²⁴ Ω·m | 10¹⁸ – 10²⁶ Ω·cm | 10²² – 10³⁰ μΩ·m |
Resistivity Conversion Formulas
Quick mathematical references for converting between international and laboratory units of electric resistivity:
- Ohm-meters to Ohm-centimeters:
Ω·cm = Ω·m × 100 - Ohm-centimeters to Ohm-meters:
Ω·m = Ω·cm ÷ 100 - Ohm-meters to Microohm-meters:
μΩ·m = Ω·m × 1,000,000 - Microohm-meters to Ohm-meters:
Ω·m = μΩ·m ÷ 1,000,000 - Ohm-centimeters to Microohm-meters:
μΩ·m = Ω·cm × 10,000 - Microohm-meters to Ohm-centimeters:
Ω·cm = μΩ·m ÷ 10,000
Frequently Asked Questions
Why is resistivity measured in Ohm-meters instead of Ohms per meter?
This is one of the most common misunderstandings in electrical engineering. In Pouillet’s Law, ρ = R × (A ÷ L). The units are ohms × (meters² ÷ meters) = ohms × meters = Ω·m. Ohms per meter (Ω/m) measures linear resistance (resistance per unit length of a wire), whereas Ohm-meters (Ω·m) measures bulk material resistivity regardless of wire diameter.
How does temperature affect resistivity?
In pure metallic conductors (like copper and aluminum), resistivity increases linearly with rising temperature due to increased electron-phonon scattering: ρ(T) = ρ₀[1 + α(T - T₀)], where α is the positive temperature coefficient. In contrast, semiconductors and carbon exhibit a negative temperature coefficient (NTC), where resistivity drops dramatically as temperature increases due to thermal generation of charge carriers.