For Singaporeans who would like to see their effective tax rate for Years of Assessment 2012 to 2017 and beyond, here's the chart. The X-axis is your total chargeable income for the year, and you can then see the tax rate that you can expect to pay. From 2017 onwards, refer to the red line. Place your mouse cursor over any individual dot to see the actual percentage at that point.
So if you're ever asked by foreigners what the tax rates for Singaporeans are, you can safely answer that it is less than 20%. It will never hit 20%, but it will come close to 20% if you earn a lot (quite a bit more than a million a year). The reason why it will never hit 20% is that the first $320k is always taxed at 13.3% so mathematically, it can never hit 20%. This is true only up to 2015 (YOA2016), after which the max will increase to 22%.
Ref: Inland Revenue Authority of Singapore, Income Tax Rates for Individuals (Locals), Available: https://www.iras.gov.sg/irashome/page04.aspx?id=1190 [Accessed 11 Apr 2015]
