Summary
If you make 109,890,560 원 a year living in South Korea, you will be taxed 25,485,340 원. That means that your net pay will be 84,405,220 원 per year, or 7,033,768 원 per month. Your average tax rate is 23.2% and your marginal tax rate is 32.7%. This marginal tax rate means that your immediate additional income will be taxed at this rate. For instance, an increase of 100 원 in your salary will be taxed 32.67 원, hence, your net pay will only increase by 67.33 원.
Bonus Example
A 1,000 원 bonus will generate an extra 673 원 of net incomes. A 5,000 원 bonus will generate an extra 3,367 원 of net incomes.