For example, a person earning $100,000 would pay a total of $23,930 in tax.
Of that $23,930, the largest amount ($6,465.34) would go to the Ministry of Social Development.
But the calculator also takes in your personal contribution to smaller government agencies, such as the Serious Fraud Office ($2.63 in our example of a $100,000 earner) and the hither-to-unknown Parliamentary Commissioner for the Environment (96 cents).
And do check out that chunk of change clipped by IRD on $123,930 tax - $1866.24.
See how they go when Mix and Mash winners are announced tomorrow, December 10.
The event is run by the Digital New Zealand business unit within the National Library of New Zealand, with Microsoft and InternetNZ as primary sponsors.