If you’re tired of grumbling about the amount of your tax dollars being spent on welfare cheats or the communists at the ABC without any hard figures to back you up, the internets are here to help.

Pseudonymous economist John Fletcher and web developer Nathan McGinness have used the 2009/10 Federal Budget forecasts and Portfolio Statements to create TaxCheck.com.au. This nifty little calculator allows punters to enter the amount of tax they expect to pay, or the amount of money they expect to earn, for the 2009/10 financial year, and presto, the income tax they contribute to various causes is calculated to the cent.

So the average Aussie, on an average annual income of just over $60,000, charitably contributes roughly $34 to veterans’ medical benefits, $31 assistance to East Asia (including assistance to Indonesia for tsunami-related construction), and $2.35 to the National Library of Australia.

Fletcher reckons his motives in making the site are purely altruistic. “It earns me no money currently nor can I conceive of any way it might in the future. So yes, basically this is about getting kicks,” he says.

Fletcher is quick to point out that the site only looks at income tax, which is responsible for only about half of what goes into the national coffers. Once GST, corporate taxes, excise taxes and so on are taken into account, “total direct and indirect contributions to federal spending could potentially be multiple times higher than the values listed above, especially when an individual’s income is relatively low.” (So all you arts students earning $16.82 annually can take heart, knowing that you’re probably still contributing something to the country’s cultural heritage scene.)

Fletcher is also realistic about the robustness of the figures, noting that the calculator makes its estimates of income tax liabilities without accounting for the Medicare Levy, Low Income Tax Offset, Family Tax Benefits or other potentially relevant factors. “[The figures] are rubbery as all hell, which means they’re on an approximately even footing with most other numbers that get chucked around in economic debates,” he says. “But yes, there are any number of critiques you can make of this … that it doesn’t account for state and territory activity, and it doesn’t account for any of the many other taxes that we pay in our daily lives.”

Sadly, detailed tax records for the shining stars of Australian politics aren’t readily available (oh, to be in Sweden!), but if we assume the following characters are earning just on average (and we could expect many to earn much more), a few interesting figures start to emerge.

Pauline Hanson: would contribute $52 towards immigration (including settlement services for migrants).

Steve Fielding: would contribute $75 towards energy efficiency and climate change action.

Wilson Tuckey: would contribute $22 towards Aboriginal and Torres Strait Islander health. And lastly,

Each Australian member of PETA: would contribute $1.75 to the dairy industry, $1.75 to the wool industry, and $5.78 to the cattle, sheep and pig industry.

Fletcher says he doesn’t expect the website to make a splash, as it essentially rearranges data that is already publicly available (www.budget.gov.au).

But if nothing else, at least now you can feel warm and fuzzy about the $3.19 you’re contributing towards natural disaster relief.