Summary
If you make 18,000 kr a year living in the region of Gladsaxe, Denmark, you will be taxed 6,051 kr. That means that your net pay will be 11,949 kr per year, or 996 kr per month. Your average tax rate is 33.6% and your marginal tax rate is 30.9%. 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 30.94 kr, hence, your net pay will only increase by 69.06 kr.
Bonus Example
A 1,000 kr bonus will generate an extra 691 kr of net incomes. A 5,000 kr bonus will generate an extra 3,453 kr of net incomes.