---
title: Numbers
---

Numbers in Sass have two components: the number itself, and its units. For
example, in `16px` the number is `16` and the unit is `px`. Numbers can have no
units, and they can have complex units. See [Units][] below for more details.

[Units]: #units

<% example(autogen_css: false) do %>
  @debug 100; // 100
  @debug 0.8; // 0.8
  @debug 16px; // 16px
  @debug 5px * 2px; // 10px*px (read "square pixels")
  ===
  @debug 100  // 100
  @debug 0.8  // 0.8
  @debug 16px  // 16px
  @debug 5px * 2px  // 10px*px (read "square pixels")
<% end %>

Sass numbers support the same formats as CSS numbers, including [scientific
notation][], which is written with an `e` between the number and its power
of 10. Because support for scientific notation in browsers has historically
been spotty, Sass always compiles it to fully expanded numbers.

[scientific notation]: https://en.wikipedia.org/wiki/Scientific_notation

<% example(autogen_css: false) do %>
  @debug 5.2e3; // 5200
  @debug 6e-2; // 0.06
  ===
  @debug 5.2e3  // 5200
  @debug 6e-2  // 0.06
<% end %>

<% heads_up do %>
  Sass doesn't distinguish between whole numbers and decimals, so for example `5
  / 2` returns `2.5` rather than `2`. This is the same behavior as JavaScript,
  but different than many other programming languages.
<% end %>

<%= partial 'documentation/snippets/number-units' %>

## Precision

<% impl_status dart: true, libsass: false, ruby: '3.5.0' do %>
  LibSass and older versions of Ruby Sass default to 5 digits of numeric
  precision, but can be configured to use a different number. It's recommended
  that users configure them for 10 digits for greater accuracy and
  forwards-compatibility.
<% end %>

Sass numbers support up to 10 digits of precision after the decimal point. This
means a few different things:

* Only the first ten digits of a number after the decimal point will be included
  in the generated CSS.

* Operations like [`==`][] and [`>=`][] will consider two numbers equivalent if
  they're the same up to the tenth digit after the decimal point.

* If a number is less than `0.0000000001` away from an integer, it's considered
  to be an integer for the purposes of functions like [`nth()`][] that require
  integer arguments.

[`==`]: ../operators/equality
[`>=`]: ../operators/relational
[`nth()`]: ../functions/lists#nth

<% example(autogen_css: false) do %>
  @debug 0.012345678912345; // 0.0123456789
  @debug 0.01234567891 == 0.01234567899; // true
  @debug 1.00000000009; // 1
  @debug 0.99999999991; // 1
  ===
  @debug 0.012345678912345  // 0.0123456789
  @debug 0.01234567891 == 0.01234567899  // true
  @debug 1.00000000009  // 1
  @debug 0.99999999991  // 1
<% end %>

<% fun_fact do %>
  Numbers are rounded to 10 digits of precision *lazily* when they're used in a
  place where precision is relevant. This means that math functions will work
  with the full number value internally to avoid accumulating extra rounding
  errors.
<% end %>