sass-site/source/documentation/values/numbers.liquid

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---
title: Numbers
introduction: >
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](#units) below for more
details.
---
{% codeExample 'numbers', false %}
@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")
{% endcodeExample %}
{% markdown %}
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
{% endmarkdown %}
{% codeExample 'scientific-notation', false %}
@debug 5.2e3; // 5200
@debug 6e-2; // 0.06
===
@debug 5.2e3 // 5200
@debug 6e-2 // 0.06
{% endcodeExample %}
{% headsUp %}
Sass doesn't distinguish between whole numbers and decimals, so for example
`math.div(5, 2)` returns `2.5` rather than `2`. This is the same behavior as
JavaScript, but different than many other programming languages.
{% endheadsUp %}
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{% render 'doc_snippets/number-units' %}
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{% markdown %}
## Precision
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{% compatibility 'dart: true', 'libsass: false', 'ruby: "3.5.0"', 'feature: "10 Digit Default"' %}
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.
{% endcompatibility %}
Sass numbers are represented internally as 64-bit floating point values. They
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support up to 10 digits of precision after the decimal point when serialized
to CSS and for the purposes of equality. This means a few different things:
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* Only the first ten digits of a number after the decimal point will be
included in the generated CSS.
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* Operations like [`==`][] and [`>=`][] will consider two numbers equivalent
if they're the same up to the tenth digit after the decimal point.
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* 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
[`list.nth()`][] that require integer arguments.
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[`==`]: /documentation/operators/equality
[`>=`]: /documentation/operators/relational
[`list.nth()`]: /documentation/modules/list#nth
{% endmarkdown %}
{% codeExample 'precision', false %}
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@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
{% endcodeExample %}
{% funFact %}
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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.
{% endfunFact %}