What is the formula to convert conductivity to resistivity?

Resistivity (rho, in ohm-metres) is the reciprocal of conductivity (sigma, in siemens per metre): rho = 1 / sigma. This means a material with a conductivity of 5.96 × 10^7 S/m (copper) has a resistivity of 1 / 5.96 × 10^7 = 1.678 × 10^-8 Ω·m. The relationship holds for any consistent pair of units: if conductivity is in S/cm, resistivity is in Ω·cm.

What is the difference between conductivity and resistivity?

Conductivity (sigma) measures how easily a material allows electrical current to flow through it. High conductivity means the material is a good conductor. Resistivity (rho) measures how strongly a material resists electrical current. High resistivity means the material is a good insulator. The two are exact reciprocals: resistivity = 1 / conductivity. Conductors like copper have very high conductivity (around 5.96 × 10^7 S/m) and very low resistivity (around 1.68 × 10^-8 Ω·m). Insulators like glass have very low conductivity and very high resistivity.

How do I convert S/cm to Ω·cm?

To convert conductivity in siemens per centimetre (S/cm) to resistivity in ohm-centimetres (Ω·cm), use the same formula: resistivity (Ω·cm) = 1 / conductivity (S/cm). For example, if a semiconductor has a conductivity of 0.01 S/cm, its resistivity is 1 / 0.01 = 100 Ω·cm. Note that 1 S/m = 0.01 S/cm, and 1 Ω·m = 100 Ω·cm, so the conversion is consistent across unit systems.

Conductivity to Resistivity Calculator

Convert electrical conductivity (sigma, in S/m or S/cm) to electrical resistivity (rho, in Ω·m or Ω·cm) using the reciprocal relationship: resistivity = 1 / conductivity. Select a common material preset or enter a custom value.

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Standard formula Reciprocal relationship rho = 1 / sigma. SI units: S/m and Ω·m.

1. Material Preset

Select a common material (or enter custom below)

2. Custom Input

Conductivity (sigma)

S/m

Please enter a positive number (scientific notation accepted, e.g. 5.96e7).

Input / output unit system

Conversion Result

Conductivity (sigma)

S/m

Resistivity (rho)
-
Ω·m

Formula used

rho = 1 / sigma

Exact reciprocal

SI Unit Result

Conductivity (S/m)-

Resistivity (Ω·m)-

Resistivity (nΩ·m)-

Resistivity (μΩ·m)-

Resistivity (mΩ·m)-

CGS Unit Result

Conductivity (S/cm)-

Resistivity (Ω·cm)-

Resistivity (mΩ·cm)-

Resistivity (μΩ·cm)-

Resistivity (nΩ·cm)-

Common Materials Reference Table

Material	Conductivity (S/m)	Resistivity (Ω·m)	Category
Copper	5.96 × 10⁷	1.68 × 10^-8	Conductor
Aluminium	3.77 × 10⁷	2.65 × 10^-8	Conductor
Iron	1.00 × 10⁷	1.00 × 10^-7	Conductor
Stainless steel	4.55 × 10⁶	2.20 × 10^-7	Conductor
Nichrome	1.56 × 10⁶	6.41 × 10^-7	Resistive alloy
Silicon (doped)	1,000	1.00 × 10^-3	Semiconductor
Silicon (intrinsic)	4.4 × 10^-4	2.27 × 10³	Semiconductor
Glass	10^-10 to 10^-14	10¹⁰ to 10¹⁴	Insulator
PTFE (Teflon)	~10^-15	~10¹⁵	Insulator

Select a material or enter a conductivity value above.

How Conductivity and Resistivity Are Related

Electrical conductivity (symbol: sigma, unit: siemens per metre, S/m) and electrical resistivity (symbol: rho, unit: ohm-metres, Ω·m) are reciprocal properties of a material. The relationship is exact:

rho = 1 / sigma and sigma = 1 / rho

Conductivity describes how easily electrical current flows through a material. A material with high conductivity (like copper at about 5.96 × 10⁷ S/m) allows current to flow with very little opposition. Resistivity describes the same property from the opposite perspective: how strongly the material resists current flow. High resistivity means the material is a good insulator.

Units and Unit Conversion

The SI unit system uses S/m for conductivity and Ω·m for resistivity. Some fields, particularly semiconductor engineering and electrochemistry, use the CGS unit system with S/cm and Ω·cm. The conversion between SI and CGS is:

1 S/m = 0.01 S/cm
1 Ω·m = 100 Ω·cm

So if you have a conductivity of 5.96 × 10⁷ S/m, this equals 5.96 × 10⁵ S/cm, and the corresponding resistivity of 1.678 × 10^-8 Ω·m equals 1.678 × 10^-6 Ω·cm (or 1.678 μΩ·cm).

Worked Example

Given: Copper has a conductivity of 5.96 × 10⁷ S/m.

Find: Resistivity of copper.

Formula: rho = 1 / sigma

Calculation: rho = 1 / (5.96 × 10⁷) = 1.678 × 10^-8 Ω·m = 16.78 nΩ·m

This matches the accepted value for the resistivity of copper at room temperature (approximately 20 °C): 1.678 × 10^-8 Ω·m or 1.678 μΩ·cm.

Conductors, Semiconductors, and Insulators

Materials are classified by their resistivity:

Conductors (metals): resistivity typically below 10^-6 Ω·m. Examples: copper, aluminium, gold, iron.
Semiconductors: resistivity typically between 10^-4 and 10⁴ Ω·m. Examples: silicon, germanium. Resistivity varies greatly with doping, temperature, and light exposure.
Insulators: resistivity typically above 10⁸ Ω·m. Examples: glass, rubber, PTFE (Teflon), quartz.

Applications

Conductivity and resistivity values are used in many engineering contexts:

Selecting cable and wire materials for electrical installations based on resistivity and cost.
Semiconductor device design, where doping levels control resistivity precisely.
Water quality testing: water conductivity is measured in S/m or mS/cm and indicates dissolved mineral content.
Soil and geotechnical surveys, where soil resistivity affects grounding electrode performance and corrosion risk.
Electromagnetic shielding, where the conductivity of a shield material determines its effectiveness.

Related Calculators

Science and Engineering Calculators
Ohm's Law Calculator: calculate voltage, current, and resistance.
Electrical Power Calculator (P = VI): power from voltage and current.
Capacitive Reactance Calculator: reactance from frequency and capacitance.

Sources and method: Reciprocal relationship rho = 1 / sigma is a standard definition in electromagnetism. Material values sourced from standard engineering references (CRC Handbook of Chemistry and Physics; Serway & Jewett, Physics for Scientists and Engineers). All calculations are exact mathematical conversions using the reciprocal formula.

Note: Resistivity and conductivity values for semiconductors vary significantly with temperature, doping concentration, and crystal structure. The values shown in the material presets are typical values at approximately 20 °C. Always verify against material datasheets for precision engineering applications.