ONE FORMULA, ONE ANSWER
Wire DC Resistance Calculator
Check conductor resistance from resistivity, length and cross-sectional area. Choose input units and calculate one value within the stated conditions.
Inputs
Calculations run in this browser. Scientific notation such as 1.2e-3 is supported. Do not group thousands.
Result
Conductor DC resistance R
Enter values and select Calculate.
R = ρ_e L / A
Assumptions
Use ρ_e,L,A>0. Assume a DC conductor of uniform material and area. Contact resistance and AC skin effects are excluded. Areas entered in mm² are converted to m².
Displayed values are floating-point approximations. Measurement uncertainty and design safety factors are not calculated.
Formula references and credits
NaNa Lab created the code, descriptions, icons and preview images. Text, figures and code from the linked references have not been reproduced.
Physical constants: NIST / CODATA 2022. The values of μ₀ and ε₀ are measured recommendations, not exact defining constants. Values and precision notes are in the source record.
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