Every year the tax tables are updated for cost of living allowance (COLA).
Your tax filing status determines what tax bracket you’re going to be at. Generally speaking, married people filing jointly (MFJ) usually receives the best tax rate.
The United States tax system is progressive, which means that as your income increases, your tax rate increases as well. But the good thing is that the highest tax rate is not applied across all of your income as different tax rate applies at each level of income. Thus, the word “tax bracket” became a common jargon and this just means  tax rate bracket your total income falls into.
Below are the 2011 tax brackets and how taxes are determined for single, Head of Household, Married Filing Joint, and Married Filing Separate.
SINGLE
| Over | But Not Over | The Tax Is | Plus |
| $0 | $8,500 | $0.00 | 10% of the amt over $ 0 |
| $8,500 | $34,500 | $850.00 | 15% of the amt over $ 8,500 |
| $34,500 | $83,600 | $4,750.00 | 25% of the amt over $ 34,500 |
| $83,600 | $174,400 | $17,025.00 | 28% of the amt over $ 83,600 |
| $174,400 | $379,150 | $42,449.00 | 33% of the amt over $174,400 |
| $379,150 | And Over | $110,016.50 | 35% of the amt over $379,150 |
HEAD OF HOUSEHOLD
| Over | But Not Over | The Tax Is | Plus |
| $0 | $12,150 | $0.00 | 10% of the amt over $ 0 |
| $12,150 | $46,250 | $1,215.00 | 15% of the amt over $ 12,150 |
| $46,250 | $119,400 | $6,235.00 | 25% of the amt over $ 46,250 |
| $119,400 | $193,350 | $24,617.50 | 28% of the amt over $119,400 |
| $193,350 | $379,150 | $45,323.50 | 33% of the amt over $193,350 |
| $379,150 | And Over | $106,637.50 | 35% of the amt over $379,150 |
MARRIED FILING JOINTLY
| Over | But Not Over | The Tax Is | Plus |
| $0 | $17,000 | $0.00 | 10% of the amt over $ 0 |
| $17,000 | $69,000 | $1,700.00 | 15% of the amt over $17,000 |
| $69,000 | $139,350 | $9,500.00 | 25% of the amt over $ 69,000 |
| $139,350 | $212,300 | $27,087.50 | 28% of the amt over $139,350 |
| $212,300 | $379,150 | $47,513.50 | 33% of the amt over $212,300 |
| $379,150 | And Over | $102,574.00 | 35% of the amt over $379,150 |
MARRIED FILING SEPARATE
| Over | But Not Over | The Tax Is | Plus |
| $0 | $8,500 | $0.00 | 10% of the amt over $ 0 |
| $8,500 | $34,500 | $850.00 | 15% of the amt over $ 8,500 |
| $34,500 | $69,675 | $4,750.00 | 25% of the amt over $ 34,500 |
| $69,675 | $106,150 | $13,543.75 | 28% of the amt over $ 69,675 |
| $106,150 | $189,575 | $23,756.75 | 33% of the amt over $106,150 |
| $189,575 | And Over | $51,287.00 | 35% of the amt over $189,575 |