Summary
If you make $18,255,900 a year living in the region of Iowa, USA, you will be taxed $8,131,517. That means that your net pay will be $10,124,383 per year, or $843,699 per month. Your average tax rate is 44.5% and your marginal tax rate is 44.7%. This marginal tax rate means that your immediate additional income will be taxed at this rate. For instance, an increase of $100 in your salary will be taxed $44.72, hence, your net pay will only increase by $55.28.
Bonus Example
A $1,000 bonus will generate an extra $553 of net incomes. A $5,000 bonus will generate an extra $2,764 of net incomes.