Tax Bracket Calculator
Estimate US federal income tax on a single-filer 2025 bracket schedule.
Overview
A US federal tax bracket calculator estimates ordinary income tax for a single filer using the 2025 marginal bracket schedule. The US tax system is progressive: each dollar of income is taxed at the rate of the bracket it falls into, not at a single flat rate based on total income. That structure produces a common point of confusion — moving into a higher bracket only increases the tax on the dollars above that threshold, not on dollars below it.
The calculator returns total federal tax owed, the effective rate (total tax as a percentage of taxable income), and the marginal rate (the bracket of the last dollar earned). It is built around the single-filer 2025 schedule and uses taxable income as the input — that is, gross income less the standard deduction or itemized deductions and any above-the-line adjustments. State income tax, FICA (Social Security and Medicare), the Alternative Minimum Tax, and credits such as the Child Tax Credit are not modelled.
How it works
The 2025 single-filer brackets, applied to taxable income, are 10%, 12%, 22%, 24%, 32%, 35%, and 37%, with thresholds adjusted for inflation. The calculator walks each bracket: tax in bracket i equals (min(taxable_income, top_i) − bottom_i) × rate_i, summed across all brackets up to and including the one containing the income. Effective rate is total_tax / taxable_income. Marginal rate is the rate of the highest bracket reached. Standard deduction for single filers in 2025 is roughly $15,000; the user enters taxable income after that deduction is applied.
Examples
- $50,000 taxable income (single 2025): 10% on the first ~$11,925, 12% on the next chunk up to ~$48,475, and 22% on the small remainder above — total around $6,053. Effective rate ≈ 12.1%, marginal rate 22%.
- $100,000 taxable income: tax ≈ $16,053. Effective rate ≈ 16.1%, marginal 24%.
- $250,000 taxable: tax ≈ $58,000. Effective ~23.2%, marginal 35%.
- $1,000,000 taxable: tax ≈ $325,000. Effective ~32.5%, marginal 37%.
FAQ
Is marginal rate the same as effective rate?
No. Marginal is the rate on the next dollar; effective is the average rate paid across all income. Effective is always lower in a progressive system.
Does crossing a bracket mean I take home less money?
No. Only the income above the bracket threshold is taxed at the higher rate. Earning more always leaves you with more, even at the bracket transition.
Does this include FICA?
No. Social Security (6.2% up to the wage base) and Medicare (1.45% plus 0.9% surtax above thresholds) are separate.
Where do credits fit in?
Credits reduce tax owed dollar-for-dollar after the bracket math; this tool does not apply them.
Are state taxes added?
No. State income tax ranges from 0% to over 13% on top of the federal calculation.