Cable resistance per length converter
Convert a cable’s resistance per length between metric and US data-sheet units, and see the voltage drop it causes.
That's about the same as AWG 12 copper. A 10 m run carrying 10 A loses 1.042 V there and back.
What it means
How resistive is that cable?
DC resistance at 20 °C. Copper’s resistance rises about 0.4 % per °C; AC adds skin effect in thick conductors.
Every unit
That cable in every unit
Learn
Three things worth knowing
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Ω/1000 ft × 3.28
Ω per 1,000 ft × 3.281 = Ω per km. AWG 14 is 2.525 Ω/kft = 8.28 Ω/km.
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Ohm’s wires
Georg Ohm found in 1827 that a wire’s resistance grows with its length, by testing wires of different lengths with a thermocouple.
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Count both wires
A 10 m cable run has 20 m of conductor: out on one wire, back on the other.
Shortcuts
Popular resistance per length conversions
Background
About cable resistance
Every conductor has resistance in proportion to its length, so cable data sheets give it per kilometer or per 1,000 feet. AWG 12 copper is 1.588 Ω per 1,000 ft, 5.21 Ω per km.
Multiply by the run length, out and back, to get the voltage drop: V = I × R.