Summary
If you make 5,268,640 Kč a year living in Czech Republic, you will be taxed 1,236,979 Kč. That means that your net pay will be 4,031,661 Kč per year, or 335,972 Kč per month. Your average tax rate is 23.5% and your marginal tax rate is 23.0%. This marginal tax rate means that your immediate additional income will be taxed at this rate. For instance, an increase of 100 Kč in your salary will be taxed 23 Kč, hence, your net pay will only increase by 77 Kč.
Bonus Example
A 1,000 Kč bonus will generate an extra 770 Kč of net incomes. A 5,000 Kč bonus will generate an extra 3,850 Kč of net incomes.