ohm meter Unit Converter

Definition of ohm meter unit

The ohm metre (Ω·m) is the SI unit of electrical resistivity. A material has a resistivity of one ohm metre when a specimen one metre long with a cross-sectional area of one square metre has a resistance of one ohm.

History of ohm meter unit

The ohm metre emerged from the development of electrical resistance measurement during the nineteenth century. The ohm itself was named after German physicist Georg Simon Ohm, whose 1827 work established the relationship between voltage, current, and resistance. As electrical science matured, researchers needed a material-specific quantity independent of specimen shape, leading to resistivity and its derived unit, ohm metre. International electrical standards gradually adopted the unit, and the International System of Units later recognized it as the coherent SI unit for resistivity, symbolized Ω·m.

Applications of ohm meter unit

Today, ohm metres are used to compare materials’ resistance to electric current. Engineers specify copper and aluminum resistivity when designing cables, while semiconductors, insulators, soils, and electrolytes are characterized for electronics, power systems, and geophysics. Laboratory measurements use a four-probe method or a known geometry, converting measured resistance into resistivity in Ω·m.

Complete list of ohm meter unit conversion