It is important to know what your marginal tax rates is when making economic decisions. The marginal tax rate is the rate in which income is taxed upon earning the next dollar of income. It also applies with deductions. If, for example, one is in the 25% marginal income tax bracket, one would receive a savings of $250 in taxes upon giving $1000 to one's church.
The marginal tax bracket depends on one's income and filing status (single, married, head of household, married filing jointly). Since investment income is tax differently, these rates pertain to earned income such as wages/salaries, self-employment income, partnership, S corp shareholder income, along with rental income.
You may find a tax rate schedule with the marginal rates here.
