Summary
If you make 82,800,636 원 a year living in South Korea, you will be taxed 17,472,865 원. That means that your net pay will be 65,327,771 원 per year, or 5,443,981 원 per month. Your average tax rate is 21.1% 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 28.64 원, hence, your net pay will only increase by 71.36 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 3,568 원 of net incomes.