Cable Resistance Calculator

Input Data and Measurement

Resistivity (\(\rho\)): This is a property of the material from which the cable is made. It measures how strongly the material resists electrical current. Resistivity is typically provided by the manufacturer of the cable and is measured in ohm-meters (Ω·m).

Length (L): This is the total length of the cable through which the current flows. Measure it in meters (m) using a tape measure or ruler.

Diameter (d): This is the thickness of the cable. Measure the diameter of the cable with a caliper or micrometer in meters (m). If you measure the circumference, you can calculate the diameter by dividing the circumference by π (approximately 3.14159).

Formula

The resistance (\(R\)) of a cable can be calculated using the following formula:

Resistance (R) = \(\frac{\rho \times L}{A}\)

Where:

• \(\rho\) is the resistivity of the cable material (in ohm-meters, Ω·m).
• L is the length of the cable (in meters, m).
• A is the cross-sectional area of the cable (in square meters, m²).

The cross-sectional area (\(A\)) of a cylindrical cable can be calculated as:

A = π × (r²)

Where:

• r is the radius of the cable (in meters, m), which is half of the diameter.