Summary
If you make $19,920 a year living in the region of California, USA, you will be taxed $2,670. That means that your net pay will be $17,250 per year, or $1,438 per month. Your average tax rate is 13.4% and your marginal tax rate is 21.1%. 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 $21.09, hence, your net pay will only increase by $78.91.
Bonus Example
A $1,000 bonus will generate an extra $789 of net incomes. A $5,000 bonus will generate an extra $3,946 of net incomes.