---
tag: 0FFXKTKKQC
kind: concept
name: Absolute value
aliases: [modulus]
msc: [26A03]
sources:
  - url: https://en.wikipedia.org/wiki/Absolute_value
    locator: lead section
same_as:
  wikidata: Q120812
  wikipedia: Absolute value
---

## Summary

The absolute value of a number is its distance from $0$. We write $|x|$ for the absolute value of $x$.
For a real number, $|x|$ is $x$ without its sign, for example $|-3| = |3| = 3$.
For a complex number $a + b i$, the absolute value is the [[modulus|0KW2X0TFBX]] $\sqrt{a^2 + b^2}$.