Summary
If you make $42,123 a year living in the region of Massachusetts, USA, you will be taxed $8,669. That means that your net pay will be $33,454 per year, or $2,788 per month. Your average tax rate is 20.6% and your marginal tax rate is 25.0%. 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 $25, hence, your net pay will only increase by $75.
Bonus Example
A $1,000 bonus will generate an extra $750 of net incomes. A $5,000 bonus will generate an extra $3,750 of net incomes.