Income Tax Estimator
Estimate US federal income tax using 2024 IRS brackets (Rev. Proc. 2023-34).
About the Income Tax Estimator
The US federal income tax is a progressive tax: income is sliced into brackets, and each slice is taxed at its own rate. The 2024 brackets - seven rates from 10% to 37% - were set by IRS Rev. Proc. 2023-34 (IR-2023-208, November 9, 2023) and apply to income earned in tax year 2024 (returns filed in early 2025). The standard deduction for 2024 is $14,600 for Single filers, $29,200 for Married Filing Jointly, and $21,900 for Head of Household. The IRS publishes annual inflation adjustments in late October or early November of the prior year, per IRC §1(f) as amended by the Tax Cuts and Jobs Act of 2017 (TCJA §1101).
The default example - a Single filer with $85,000 gross income and no additional deductions - has a $14,600 standard deduction, leaving $70,400 of taxable income. Tax computed bracket by bracket: 10% on the first $11,600 ($1,160), 12% on $11,601-$47,150 ($4,266), 22% on $47,151-$70,400 ($5,115). Total federal tax: $10,541. Marginal rate: 22% - the rate on the next dollar earned. Effective rate: 12.40% ($10,541 / $85,000) - the average rate across all brackets. Take-home pay: $74,459.
Marginal and effective rates answer different questions. The marginal rate (22%) tells you the tax on the next dollar earned - useful for deciding whether to take on extra work, convert a Traditional IRA to a Roth, or realize a capital gain. The effective rate (12.40%) tells you what fraction of total income went to federal tax - useful for budgeting and for comparing progressivity across incomes. The two differ because the lower brackets are taxed at lower rates; the difference grows as income rises.
This calculator applies the standard deduction by default. Taxpayers whose itemized deductions (mortgage interest, state and local taxes up to the $10,000 SALT cap per TCJA §11023, charitable contributions, medical expenses above 7.5% of AGI per IRC §213) exceed the standard deduction should use the "Additional Deductions" field to enter the excess over the standard. After TCJA's SALT cap, only about 10% of filers itemize (Tax Policy Center 2024 estimate).
How It Works
The federal income tax is computed bracket by bracket on taxable income (gross income minus deductions):
Taxable Income = Gross Income - Standard Deduction - Additional Deductions
Tax = sum over brackets of (amount in bracket x bracket rate)
2024 brackets (IRS Rev. Proc. 2023-34):
Single:
10% on $0 - $11,600
12% on $11,601 - $47,150
22% on $47,151 - $100,525
24% on $100,526 - $191,950
32% on $191,951 - $243,725
35% on $243,726 - $609,350
37% on $609,351+
Married Filing Jointly:
10% on $0 - $23,200
12% on $23,201 - $94,300
22% on $94,301 - $201,050
24% on $201,051 - $383,900
32% on $383,901 - $487,450
35% on $487,451 - $731,200
37% on $731,201+
Head of Household:
10% on $0 - $16,550
12% on $16,551 - $63,100
22% on $63,101 - $100,500
24% on $100,501 - $191,950
32% on $191,951 - $243,700
35% on $243,701 - $609,350
37% on $609,351+
2024 Standard Deduction:
Single: $14,600
Married Filing Jointly: $29,200
Head of Household: $21,900For the default Single filer with $85,000 gross income and $0 additional deductions: taxable income = $85,000 - $14,600 - $0 = $70,400. Tax by bracket: 10% on first $11,600 = $1,160; 12% on $11,601-$47,150 = $4,266; 22% on $47,151-$70,400 = $5,115. Total: $10,541. Marginal rate: 22%. Effective rate: $10,541 / $85,000 = 12.40%. Take-home: $74,459.
The code iterates through the brackets, computing the tax for each segment as (min(taxable, hi) - lo) x rate and accumulating the total. The marginal rate is the rate of the highest bracket that taxable income reaches. The effective rate is total tax divided by gross income, which gives the average tax burden. Note that moving from one bracket to the next affects only the income above the threshold - the lower brackets stay at their original rates. This is the cornerstone of progressivity.
Worked Examples
Default example: Single filer, $85,000 gross income, $0 additional deductions. Standard deduction: $14,600. Taxable income: $70,400. Tax: 10% on $11,600 = $1,160; 12% on $35,550 = $4,266; 22% on $23,250 = $5,115. Total federal tax: $10,541. Marginal rate: 22%. Effective rate: 12.40%. Take-home: $74,459.
Married Filing Jointly with $170,000 combined gross income. Standard deduction: $29,200. Taxable income: $140,800. Tax: 10% on $23,200 = $2,320; 12% on $71,100 = $8,532; 22% on $46,500 = $10,230. Total: $21,082. Marginal rate: 22%. Effective rate: 12.40% (identical to Single at half the income, because MFJ brackets are exactly twice the Single brackets through the 32% bracket). Take-home: $148,918.
Head of Household with $85,000 gross income. Standard deduction: $21,900. Taxable income: $63,100. Tax: 10% on $16,550 = $1,655; 12% on $46,550 = $5,586. Total: $7,241. Marginal rate: 12% (one bracket lower than Single on the same income, because HoH brackets are wider). Effective rate: 8.52%. Take-home: $77,759. The HoH status saves $3,300 in tax versus Single on the same $85,000 income - the financial recognition that HoH filers support a qualifying dependent.
When to Use This Tool
Use the income tax calculator when you need to:
- Estimate your 2024 federal income tax liability before filing Form 1040 in April 2025.
- Compare tax outcomes between Single, Married Filing Jointly, and Head of Household filing statuses - useful for newlyweds and for parents deciding who claims the child.
- Project the tax impact of a raise, bonus, or side-hustle income on your marginal rate.
- Decide whether to take the standard deduction or itemize (if itemized deductions exceed $14,600 Single / $29,200 MFJ / $21,900 HoH).
- Estimate the after-tax cost of a Roth IRA conversion, which adds converted amounts to ordinary income.
- Plan withholding adjustments on Form W-4 to avoid a surprise tax bill or large refund.
- Teach progressive taxation concepts - marginal versus effective rate - in a classroom or financial-literacy setting.
Limitations & Disclaimer
This calculator computes US federal income tax only (no state, no AMT, no SECA) using 2024 IRS brackets and standard deductions (Rev. Proc. 2023-34). It does not handle itemized deductions beyond what you enter, capital gains, qualified dividends, the Earned Income Tax Credit, Child Tax Credit, Additional Child Tax Credit, self-employment tax, Net Investment Income Tax (IRC §1411), or alternative minimum tax. For an actual tax filing, use IRS Form 1040 and the relevant schedules; consult a licensed tax professional for advice tailored to your situation. This tool is not tax, accounting, or legal advice. See our disclaimer for full terms.
Frequently Asked Questions
What is the difference between marginal and effective tax rate?
Marginal rate is the tax rate on the next dollar of income (the rate of the highest bracket you reach). Effective rate is total tax divided by total income - the average rate. A Single filer at $85,000 has a 22% marginal rate but a 12.40% effective rate, because most of their income falls in the lower 10% and 12% brackets. Marginal rate is relevant for decisions about additional income; effective rate is relevant for budgeting.
Are these the official 2024 brackets?
Yes. The 2024 federal income tax brackets and standard deductions were set by IRS Rev. Proc. 2023-34 (IR-2023-208, November 9, 2023) and apply to income earned in tax year 2024 (returns filed in early 2025). The IRS publishes annual inflation adjustments in late October or early November of the prior year, per IRC §1(f) as amended by TCJA §1101.
Does this calculator include state income tax?
No. This calculator computes only federal income tax. State income tax rates vary widely - from 0% in seven states (Alaska, Florida, Nevada, South Dakota, Texas, Washington, Wyoming) to a top marginal rate of 13.3% in California (per the Federation of Tax Administrators 2024 survey). Add state tax on top of federal for total income-tax burden.
What is the SALT cap and does it affect me?
The Tax Cuts and Jobs Act of 2017 (TCJA §11023) capped the state and local tax (SALT) deduction at $10,000 per return through 2025. Before TCJA, taxpayers could deduct all state and local income, property, and sales taxes. The cap is one reason only about 10% of filers now itemize (Tax Policy Center 2024 estimate). The cap is scheduled to expire after 2025 unless Congress extends it.
Should I take the standard deduction or itemize?
Take whichever is larger. For 2024, the standard deduction is $14,600 Single / $29,200 MFJ / $21,900 HoH. Itemize only if your total of mortgage interest, charitable contributions, SALT (capped at $10,000), and medical expenses above 7.5% of AGI (per IRC §213) exceeds that figure. According to Tax Policy Center 2024 data, roughly 90% of filers now take the standard deduction.
Does this calculator account for the Alternative Minimum Tax (AMT)?
No. The AMT (IRC §55) is a parallel tax system that disallows certain deductions (notably SALT) and applies a flat 26% or 28% rate to a broader income base. The TCJA raised the AMT exemption significantly, so only about 0.1% of filers paid AMT in 2023 (Tax Policy Center estimate). If your income is above $500,000 Single / $1,000,000 MFJ and you have large capital gains or incentive stock options, file Form 6251 to check.
What about self-employment tax?
Self-employed individuals (sole proprietors, gig workers, independent contractors) pay Self-Employment Contributions Act tax (SECA, IRC §1401) of 12.4% Social Security on the first $168,600 of net earnings (2024 limit per SSA) plus 2.9% Medicare on all net earnings - the equivalent of both halves of FICA. This is in addition to federal income tax and is not included here; compute it on Schedule SE attached to Form 1040.
Last updated: September 9, 2026 · Author: HT99 Tools Editorial Team