Rails number to percentage helper

February 21, 2008

In the next few days I’m going to quickly touch on a few of Rail’s number helper methods. Lately I’ve been doing a lot of mathematical calculations that require percentages, the number_to_percentage method is quite handy.

# number_to_percentage(number, options = {})
#  Formats a number as a percentage string (e.g., 65%). You can customize the format in the options hash.
# Options
#  :precision - Sets the level of precision (defaults to 3).
#  :separator - Sets the separator between the units (defaults to ".").
# Examples
 
# returns 100.000%
number_to_percentage(100)                         
 
# returns 100%
number_to_percentage(100, :precision => 0)        
 
# returns 302.24399%
number_to_percentage(302.24398923423, :precision => 5)