Rails: How to print a decimal as a percent?

You are probably going to want to use the number_to_percentage method. From the documentation, here are some examples of how to use it:

number_to_percentage(100)                                        # => 100.000%number_to_percentage("98")                                       # => 98.000%number_to_percentage(100, precision: 0)                          # => 100%number_to_percentage(1000, delimiter: '.', separator: ',')       # => 1.000,000%number_to_percentage(302.24398923423, precision: 5)              # => 302.24399%number_to_percentage(1000, locale: :fr)                          # => 1 000,000%number_to_percentage("98a")                                      # => 98a%number_to_percentage(100, format: "%n  %")                       # => 100  %

Options:

:locale - Sets the locale to be used for formatting (defaults to current locale).:precision - Sets the precision of the number (defaults to 3).:significant - If true, precision will be the # of significant_digits. If false, the # of fractional digits (defaults to false).:separator - Sets the separator between the fractional and integer digits (defaults to “.”).:delimiter - Sets the thousands delimiter (defaults to “”).:strip_insignificant_zeros - If true removes insignificant zeros after the decimal separator (defaults to false).:format - Specifies the format of the percentage string The number field is %n (defaults to “%n%”).

Or you can write some ruby like the following:

 class Numeric   def percent_of(n)    self.to_f / n.to_f * 100.0   end endp (1).percent_of(10)    # => 10.0  (%)p (200).percent_of(100) # => 200.0 (%)p (0.5).percent_of(20)  # => 2.5   (%)

You can use number_to_percentage helper to print number as percentage in your view. if your number is between 0 and 1 then you can achieve it with:

number_to_percentage(@number * 100, precision: 0) 

see the documentation