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Electrical Calculators

Wire Resistance Calculator

Verified formula Updated Jun 2026 Private — runs on your device

Enter details
m
mm²
Verified formula Private

Wire resistance

0.11200

For general information only — not financial, tax, legal or medical advice. Verify before you rely on it.

How to use the Wire Resistance Calculator

The Wire Resistance Calculator works out your wire resistance in an instant. Enter wire length, cross-section area and resistivity (Ω·mm²/m) and the result updates as you type — it is free, needs no sign-up, and runs entirely in your browser so your figures stay private.

  1. Enter the wire length.
  2. Enter the cross-section area.
  3. Enter the resistivity (Ω·mm²/m).
  4. Read off your wire resistance — the calculator updates automatically, with no button to press.

Formula

The Wire Resistance Calculator uses the formula:

Wire resistance = Resistivity (Ω·mm² ÷ m) × Wire length ÷ Cross-section area

Worked example

For example, with wire length of 10 m, cross-section area of 1.5 mm² and resistivity (Ω·mm²/m) of 0.0168, the wire resistance is 0.11200.

Inputs used
Wire length 10 m
Cross-section area 1.5 mm²
Resistivity (Ω·mm²/m) 0.0168
Results
Wire resistance 0.11200

Results are estimates for educational use, not professional advice.

Key terms explained

Area
The amount of two-dimensional space a shape covers, measured in square units.

Frequently asked questions

Use R = resistivity × length ÷ area. A 10 m copper wire of 1.5 mm² has a resistance of about 0.112 ohms.

Copper is about 0.0168 Ω·mm²/m and aluminium about 0.0282. The default is copper; change it for other materials.

A larger cross-section gives charge more room to flow, so resistance falls as area rises, for the same length and material.

Resistance grows with length, causing voltage drop on long runs. For long cables, use a larger area to keep resistance low.

Enter the wire length. Enter the cross-section area. Enter the resistivity (Ω·mm²/m). Read off your wire resistance — the calculator updates automatically, with no button to press.

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