Summary
If you make 77,791,992 원 a year living in South Korea, you will be taxed 16,038,867 원. That means that your net pay will be 61,753,125 원 per year, or 5,146,094 원 per month. Your average tax rate is 20.6% and your marginal tax rate is 28.6%. 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 28.63 원, hence, your net pay will only increase by 71.37 원.
Bonus Example
A 1,000 원 bonus will generate an extra 714 원 of net incomes. A 5,000 원 bonus will generate an extra 3,569 원 of net incomes.