Electric Conductivity Converter

Electric conductivity, denoted by sigma (σ), is an intrinsic material property that quantifies how easily electric current flows through a substance. It is the reciprocal of electric resistivity: σ = 1/ρ. While resistivity characterises opposition to current, conductivity characterises facilitation of current. The two properties are used interchangeably depending on whether a material is being described as a conductor (high σ) or an insulator (low σ). The field-form of Ohm's law, J = σE, expresses this: the current density J equals the product of conductivity and electric field strength E.

The SI unit of electric conductivity is the siemens per meter (S/m). This unit spans an extraordinary range across materials: from silver at approximately 6.3 × 10⁷ S/m (the highest conductivity metal) through intrinsic silicon at 1.56 × 10⁻³ S/m and pure water at 5.5 × 10⁻⁶ S/m to polytetrafluoroethylene (PTFE/Teflon) at around 10⁻¹⁶ S/m — spanning 23 orders of magnitude. The S/m unit is used in electromagnetic finite-element modelling, materials science, and all branches of electrical engineering.

At the low end of the conductivity scale, the picosiemens per meter (pS/m) is used for characterising high-purity dielectric materials. Ultra-pure deionised water used in semiconductor manufacturing has conductivity as low as 0.055 µS/cm = 5.5 × 10⁻³ µS/m = 5500 pS/m. Transformer oils, cable insulation materials, and vacuum capacitor dielectrics may have conductivities measured in pS/m. Monitoring conductivity in this range is critical for detecting ionic contamination that could cause dielectric breakdown.

The mho per meter (mho/m) and mho per centimeter (mho/cm) are older equivalents of S/m and S/cm respectively. One mho/m = 1 S/m exactly (mho and siemens are the same unit). One mho/cm = 100 S/m, since 1 cm = 0.01 m. The mho/cm unit is common in historical chemical conductivity tables and some American environmental testing standards. Most modern instruments report conductivity in S/m or µS/cm, but engineers reading older data frequently need these conversions.

In the CGS electromagnetic unit (EMU) system, conductivity is expressed in abmho per meter (abmho/m) and abmho per centimeter (abmho/cm). Since 1 abmho = 10⁹ S, 1 abmho/m = 10⁹ S/m. This means the conductivity of copper would be about 0.0596 abmho/m in CGS-EMU — a much smaller number than in SI. These units appear in pre-1960 electromagnetic engineering texts.

The statmho per meter (statmho/m) and statmho per centimeter (statmho/cm) are CGS electrostatic unit (ESU) equivalents. Since 1 statmho ≈ 1.113 × 10⁻¹² S, 1 statmho/m ≈ 1.113 × 10⁻¹² S/m. These tiny values reflect the ESU system's foundation in electrostatic phenomena. Conductivity in statmho/cm appears in some Gaussian-unit plasma physics calculations.

Applications of conductivity measurement span virtually every technical field. In hydrogeology, groundwater conductivity (typically 100–2000 µS/cm) reveals dissolved mineral content and identifies contamination plumes. In food and beverage processing, inline conductivity probes monitor concentration of cleaning agents during clean-in-place (CIP) cycles and verify rinse water purity. In semiconductor processing, ultra-pure water conductivity specifications ensure contamination-free wafer cleaning. In corrosion engineering, soil conductivity predicts corrosive aggressiveness toward buried pipelines and cables.

This converter supports all eight electric conductivity units: S/m, pS/m, mho/m, mho/cm, abmho/m, abmho/cm, statmho/m, and statmho/cm. Select your source and target units, enter a value, and get an instant precise conversion. Whether you are working in water treatment, materials research, electromagnetic simulation, or historical unit translation, Unit Converters Lab delivers reliable results with no downloads or registration required.