Suppose you work in New Zealand, would like to earn a given net weekly income (for 52 weeks per year) after income tax, and would like to work a given number of hours per week (for 47 weeks per year; NZ workers get 4 weeks annual leave plus roughly 1 week of public holidays). What gross hourly income must you earn?
To answer that question, i used the 1 April 2012 to 31 March 2013 NZ income tax rates for individuals, wrote this Python program, and used it with Sage to make this table:
The gross hourly incomes needed are displayed in the main body of the table in New Zealand dollars, rounded to the nearest dollar and excluding GST. For example, to earn $1200/week after tax, working 25 hours/week, you need to earn $68/hour before tax.