What is the Tax Bracket Calculator?
This calculator estimates your 2026 US federal income tax using the official progressive tax brackets for Single and Married Filing Jointly filers. It applies each marginal rate only to the income that falls within that bracket, then reports your total tax, marginal rate, effective rate, and after-tax income. It does not account for state taxes, deductions beyond what you enter as taxable income, or credits.
How to use it
Enter your taxable income (income after deductions) and choose your filing status. The result shows the estimated federal tax owed, the marginal rate (the rate on your last dollar), the effective rate (average rate across all income), and what's left after tax.
The formula explained
The US uses a progressive system: only the portion of income inside each bracket is taxed at that bracket's rate. For each bracket with lower bound \(l\), upper bound \(u\), and rate \(r\), the tax is \((\min(\text{income}, u) - l) \times r\), summed over all brackets the income reaches.
$$\text{Tax} = \sum_{i} \big(\min(I, u_i) - l_i\big)^{+} \cdot r_i$$
Worked example
For a Married Filing Jointly return with $100,000 taxable income (2026): the first $24,800 is taxed at 10% = $2,480; the remaining $75,200 falls entirely within the 12% band (which for 2026 runs up to $100,800) and is taxed at 12% = $9,024. There is no 22% portion because the 12% ceiling rose to $100,800. Total =
$$\$2{,}480 + \$9{,}024 = \mathbf{\$11{,}504}$$The effective rate is
$$\frac{11{,}504}{100{,}000} = 11.504\%,$$leaving $88,496 after tax.
FAQ
What's the difference between marginal and effective rate? Your marginal rate is the rate applied to your highest dollar of income; your effective rate is your total tax as a percentage of all income, which is always lower.
Is this based on gross or taxable income? Enter taxable income — your gross income minus the standard or itemized deductions.
Does this include state taxes? No, this is federal income tax only and excludes state tax, FICA, credits, and the alternative minimum tax.
