E-Textiles

Conductive Yarn Resistance & Voltage Drop Calculator

A conductive yarn at 25 ohms per metre is not wire. Half a metre of it can eat a fifth of a 3.3 volt rail before the sensor sees anything.

Trace Conductive yarn
Ω/m
m
Circuit Operating point
V
mA
%

Voltage Drop

— V

Lost along the conductive trace at the working current

Circuit Behaviour

Trace Resistance
— Ω
Drop as Share of Supply
— %
Voltage at the Load
— V
Power Dissipated in Trace
— mW
Longest Trace Within Budget
— m

Resistance of coated yarns rises with washing, flexing and corrosion of the metal layer, so design against an end-of-life value rather than the datasheet figure. Power dissipated in the trace is heat in contact with skin — check it against a comfort limit as well as an electrical one.

Conductive Yarn Resistance & Voltage Drop Calculator — free, with the formula and a worked example, at Textile School.