# Why use mm² in Power Cables?

**URL:** <https://forumautomation.com/t/why-use-mm-in-power-cables/14444>\
**Category:** Electrical\
**Tags:** cablesizing, cable\
**Created:** [September 25, 2026, 2:56am UTC](https://forumautomation.com/t/why-use-mm-in-power-cables/14444 "2026-09-25T02:56:46Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![TSRS](https://forumautomation.com/user_avatar/forumautomation.com/tsrs/32/8023_2.png) [@TSRS](https://forumautomation.com/u/TSRS)\
**Post date:** [September 25, 2026, 2:56am UTC](https://forumautomation.com/t/why-use-mm-in-power-cables/14444/1 "2026-09-25T02:56:46Z")

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## Why use mm² in Power Cables?

**[Power cable](https://forumelectrical.com/factors-for-power-cables-selection/)** conductor size is measured in square millimeters (mm²) because the most important factor is the cross-sectional area of the conductor not its diameter.

The conductor area directly determines how much current the cable can safely carry and how much electrical resistance it has.

 ![1](https://cdn.forumautomation.com/original/2X/8/8def26f30661b6af01a322ac333deb4f12e58cb6.jpeg)

## Why use mm²?

## 1). Current Carrying Capacity

The amount of current a cable can safely carry depends on its cross-sectional area.

Larger area = Lower resistance = Higher current carrying capacity.

## 2). Lower Electrical Resistance

Electrical resistance is inversely proportional to the conductor’s area.

A larger mm² conductor reduces voltage drop and power losses.

## 3). Accurate for Solid and Stranded Conductors

Cables can be solid or made of many strands.

Diameter alone cannot accurately represent the total amount of copper (or) aluminum.

mm² provides the true conductor metal area regardless of construction.

> **[Selection of Power Cables](https://forumelectrical.com/factors-for-power-cables-selection/)**
>
> The proper cable selection and implementation for power distribution & utilisation are the focus of discussion in this technical post.