Calculate constantan wire resistance from dimensions, gauge, resistivity, and temperature, while estimating voltage drop, power loss, conductance, and resistance per unit length and design.
Material properties vary by alloy composition and manufacturer. Custom values are available for precise work.
Constantan is a copper-nickel resistance alloy. It has stable electrical behavior across moderate temperatures. Its resistivity is much higher than copper. This makes constantan useful in resistance applications. Thermocouples also commonly use constantan with other metals. Actual composition can slightly change published electrical values.
Wire resistance increases with greater conductor length. Resistance decreases when cross-sectional area becomes larger. A thicker wire therefore has lower resistance. The calculator uses the standard resistivity relationship. Circular diameter values are converted into cross-sectional area. AWG values are converted using the standard gauge equation. Temperature correction uses the entered coefficient value. Constantan normally has a very small temperature coefficient. That property helps produce comparatively stable resistance values.
Use measured dimensions whenever accurate results are important. Select consistent units before entering each value. The default resistivity suits many general calculations. Manufacturer data remains better for precision engineering work. Enter custom resistivity when your alloy specification differs. Add current to estimate voltage drop and heating. Higher current causes much greater resistive power loss. Power varies with the square of current.
The tool reports resistance in several useful scales. It also shows resistance per meter and foot. Conductance is the reciprocal of electrical resistance. Voltage drop follows Ohm's law using entered current. Power loss estimates electrical energy converted into heat. Required length mode solves wire length directly. Diameter mode finds a circular wire size. Area mode returns the needed conductor area. These inverse modes help with practical wire selection.
Real installations can differ from theoretical predictions. Contact resistance may affect low-resistance measurements. Wire tolerances can change diameter and area. Temperature gradients may also change measured resistance slightly. Use calibrated instruments for laboratory verification. Always apply suitable electrical safety practices during testing. Accurate inputs produce better engineering estimates and comparisons overall.
| Length | Diameter | Area | Approx. resistance |
|---|---|---|---|
| 1 m | 0.50 mm | 0.196 mm² | 2.50 Ω |
| 5 m | 0.50 mm | 0.196 mm² | 12.48 Ω |
| 10 m | 0.50 mm | 0.196 mm² | 24.96 Ω |
| 10 m | 1.00 mm | 0.785 mm² | 6.24 Ω |
About 4.9×10⁻⁷ Ω·m is a common general value. Use manufacturer data for precision work.
It offers relatively high resistivity and low temperature sensitivity.
Yes. Select the AWG calculation mode and enter the gauge number.
Yes, but the change is usually small compared with many metals.
Yes. Enter current and the calculator applies V = IR.
Yes. Use the CSV or PDF buttons above the results.
Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.