Summary
If you make 420,000 kr a year living in the region of Nordfyns, Denmark, you will be taxed 139,987 kr. That means that your net pay will be 280,013 kr per year, or 23,334 kr per month. Your average tax rate is 33.3% and your marginal tax rate is 36.0%. This marginal tax rate means that your immediate additional income will be taxed at this rate. For instance, an increase of 100 kr in your salary will be taxed 36 kr, hence, your net pay will only increase by 64 kr.
Bonus Example
A 1,000 kr bonus will generate an extra 640 kr of net incomes. A 5,000 kr bonus will generate an extra 3,200 kr of net incomes.