Wire Resistance Calculator

Electrical resistivity is a fundamental concept in electromagnetism and electrical engineering. It characterizes a material's inherent opposition to the flow of electric current. The electrical resistivity of a wire, in particular, depends on the wire's material, length, and cross-sectional area. This tutorial will guide you through the underlying principles and the formulas used to calculate the resistivity of a wire.

Wire Resistivity Calculator
Wire Resistance Calculator Results
Electrical Resistivity = ohms .m

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Example Formula

The formula used to calculate the electrical resistivity of a wire is:

ρ = R × (A / L)


  1. ρ is the electrical resistivity (in ohm meters).
  2. R is the electrical resistance of the wire (in ohms).
  3. A is the cross-sectional area of the wire (in square meters).
  4. L is the length of the wire (in meters).

Who wrote/refined the formula

The formula was initially established based on the empirical observations and experiments conducted by Georg Simon Ohm in 1827, known as Ohm's law. The specific formula for resistivity was later derived and is a standard formula used in the field of electrical engineering and physics.

Real Life Application

Electrical resistivity plays a key role in the design and manufacturing of electrical wires and cables used in various industries. For example, engineers use this formula to calculate the suitable thickness and material of wires needed to transmit electricity over long distances with minimal energy loss.

Key individuals in the discipline

Georg Simon Ohm, a German physicist, is the key individual associated with the concept of electrical resistance. His work, known as Ohm's law, forms the basis for much of what we understand about electricity and electronics today. His experiments and observations have been integral in shaping the field of electrical engineering.

Interesting Facts

  1. Electrical resistivity is a major factor in determining the efficiency of power transmission lines. High resistivity results in more energy loss as heat.
  2. The discovery of superconductivity, a state where resistivity becomes zero, revolutionized the field of electronics and paved the way for technologies like Magnetic Resonance Imaging (MRI).
  3. Ohm's law, and by extension the formula for resistivity, are foundational to modern electrical and electronic systems, making possible everything from smartphones to electric vehicles.


Understanding the concept of electrical resistivity is fundamental to the fields of physics and electrical engineering. The ability to calculate and manipulate the resistivity of a wire allows engineers to design more efficient and effective electrical systems. This foundational concept is behind the vast majority of modern technology, underlining the importance of physics in driving technological advancement.

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