Wire Resistance Calculator
Compute wire resistance R = rho * L / A from length and cross-sectional area, defaulting to copper resistivity (1.68e-8 ohm-meter at 20 degrees Celsius); area is given in square millimeters and converted to square meters.
Description
Compute wire resistance R = rho * L / A from length and cross-sectional area, defaulting to copper resistivity (1.68e-8 ohm-meter at 20 degrees Celsius); area is given in square millimeters and converted to square meters.
Wire Resistance Calculator: Compute wire resistance R = rho * L / A from length and cross-sectional area, defaulting to copper resistivity (1.68e-8 ohm-meter at 20 degrees Celsius); area is given in square millimeters and converted to square meters.
When to use Wire Resistance
Use this electronics calculation for a first-pass component, converter, signal, motor, or sensor estimate when the stated operating conditions and units match the device data.
- Cross-section (mm^2)
- Conductor cross-sectional area.
- Length (m)
- One-way conductor length; double it for a full out-and-back loop.
- Resistivity (Ω·m)
- Material resistivity; defaults to copper. Aluminum is about 2.65e-8 ohm-meter.
How Wire Resistance works
Compute wire resistance R = rho * L / A from length and cross-sectional area, defaulting to copper resistivity (1.68e-8 ohm-meter at 20 degrees Celsius); area is given in square millimeters and converted to square meters. The tool evaluates the supplied inputs together and returns the named outputs below; it does not infer omitted operating conditions or change the units shown.1
- Resistance (Ω)
- Resistance of the specified conductor length.
Limitations and assumptions
- Compact electronics formulas omit some combination of tolerances, temperature drift, bandwidth, loading, parasitics, noise spectrum, nonlinearity, clipping, calibration, layout, and device-specific limits. Typical datasheet values are not guaranteed limits.
- Use finite inputs in the displayed units and preserve more precision than the final presentation requires. Independently verify safety-critical, financial, compliance, or production decisions.
Alternative or Complementary approaches
Check the result against the current datasheet and worst-case operating corners, then verify the circuit or measurement with simulation and bench testing where failure matters.
References
-
Electrical resistivity and conductivity — Wikipedia contributors
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