Summary
If you make $20,400 a year living in the region of Illinois, USA, you will be taxed $3,318. That means that your net pay will be $17,082 per year, or $1,423 per month. Your average tax rate is 16.3% and your marginal tax rate is 23.3%. This marginal tax rate means that your immediate additional income will be taxed at this rate. For instance, an increase of $100 in your salary will be taxed $23.31, hence, your net pay will only increase by $76.69.
Bonus Example
A $1,000 bonus will generate an extra $767 of net incomes. A $5,000 bonus will generate an extra $3,835 of net incomes.