Other Issues affecting Income Tax Rates (2011-2012 Tax Year)
The five income brackets define Australian income tax rates, but you also need to take the Medicare Levy, Medicare Levy Surcharge and the Low Income Tax Offset into account when working out your total tax payable per year.
Every Australian must pay the Medicare Levy at 1.5% of their income. As well as this, taxpayers who earn above $80,000 and don't have private health insurance are usually required to pay the Medicare Levy Surcharge which is a further 1% of their taxable income.
If you earn less than $67,500, you will receive the Low Income Tax Offset which provides those earning less than $30,000 with a rebate of $1500. This amount is reduced by 4c for every dollar an individual earns above $30,000 up to $67,500. If you earn less than $16,000, this offset will make your tax payable = zero.