Using Sass, how to convert a percentage to a decimal?

here's @Rhysyngsun ruby script as a scss function:

@function decimal($v) {
    @if (type_of($v) != number OR unit($v) != "%") {
        @error "decimal: `#{$v}` is not a percent";
    }
    @return $v / 100%;
}

While SASS doesn't provide this as a built-in function you could certainly add a custom function to perform the conversion. Taking a look at the source for percentage(), I took a stab at what a decimal() function would look like:

def decimal(value)
  unless value.is_a?(Sass::Script::Number) && value.unit_str == "%"
    raise ArgumentError.new("#{value.inspect} is not a percent")
  end
  Sass::Script::Number.new(value.value / 100.0)
end

You can use Sass math to convert a percentage to a decimal value by dividing the percentage by 100%.

When you divide a percentage by a percentage, the result is a decimal.

Sass code:

$percent: 44%
.foo
  opacity: $percent / 100%

Compiled to CSS:

.foo { opacity: 0.44; }