Hello bigup401,

I do not know if you saw my updated answer but here is an example that you can use a module and it will do the calculation for you (see below):

#!/usr/bin/perl
use strict;
use warnings;
use feature 'say';
use Math::PercentChange qw(f_percent_change);

my $from = 10;
my $to   = 15;
say f_percent_change($from, $to, "%.03f");

__END__

$ perl test.pl
50.000%
[download]

Hope this helps, BR.