Connecticut Tax Calculator
Connecticut has a progressive income tax with a top rate of 6.99% — paired with one of the highest property tax rates in the Northeast.
Connecticut's seven-bracket income tax ranges from 2% to 6.99%, with the top rate applying to single filers with taxable income above $500,000 and joint filers above $1,000,000. The state completed a phase-out of the income tax on Social Security benefits for lower-income retirees in 2023 and is now considering extending full Social Security exemption. CT does not allow a standard deduction — taxpayers must itemize, though the federal itemized deduction typically applies. Property taxes are well above the national mean at ~1.79%, among the highest in the Northeast. The combined sales tax is ~6.35%, with no local additions. Connecticut's tax structure is supplemented by a 7.5% corporation tax (among the highest in the US), reflecting the state's reliance on wealthy residents and corporate entities. The state's overall tax burden is high, fueling population outflows since 2018, especially to lower-tax Florida and the Carolinas. Hartford and Fairfield counties remain among the wealthiest ZIP codes in the country despite these outflows.
Income Tax Calculator
Enter Your Income Details
See how much federal and state income tax you'll owe using 2025 brackets
How US Income Tax Works
Progressive Brackets
The US uses a progressive tax system where higher income is taxed at higher rates.
Standard Deduction
Your income up to the standard deduction amount is not taxed (${DEDUCTIONS_BY_YEAR[input.year]?.single ?? 15000} single, ${DEDUCTIONS_BY_YEAR[input.year]?.married ?? 30000} married in 2025).
Marginal vs Effective Rate
Your marginal rate is the highest bracket you reach; your effective rate is total tax divided by income.
Important Notes:
- 2025 tax brackets: This calculator uses 2025 federal tax brackets and standard deduction amounts.
- State taxes vary: Some states have no income tax (TX, FL, WA), while others range from 1% to 13.3%.
- This is an estimate: Actual tax liability depends on credits, additional deductions, and other income sources.
- Not tax advice: Consult a tax professional for personalized guidance.
How our income tax calculator works
Enter your income
Type your annual gross income from wages, self-employment, investments, or retirement. Include all sources for the most accurate estimate.
Select filing status
Choose single, married filing jointly, or head of household. We use 2025 IRS brackets and the standard deduction for your status.
Add deductions and credits
Enter pre-tax deductions (401k, HSA) and tax credits (child tax credit, education credit). The calculator adjusts your taxable income and final tax.
Key things to know about our income tax calculator:
- Federal brackets: 10% on first ~11,925 dollars, 12% on 11,926-48,475, 22% on 48,476-103,350, 24% on 103,351-197,300, up to 37% for high earners.
- State tax varies: Some states (FL, TX, WA, NV, AK, SD, TN, WY, NH) have no income tax. Others range from 0-13%. We use your states current brackets.
- Use the calculator: For take-home pay math, use the paycheck calculator. For business or self-employment tax, pair with the self-employment tax estimator.
For related calculations, try our paycheck calculator.
Connecticut State Taxes at a Glance (2025)
| Item | Value | Notes |
|---|---|---|
| Income tax structure | 2.00% – 6.99% | 2025 tax-year |
| Standard deduction (single) | $0 | $0 = must itemize |
| Standard deduction (married) | $0 | Filing jointly |
| Combined sales tax | 6.35% | State + average local |
| Effective property tax | 1.79% | Residential |
| Key state note | Top rate 6.99% — no standard deduction | |
Numbers reflect 2025 state-level rules and may not include local income taxes (NYC, Philadelphia, etc.). Use the calculator above to model your specific scenario.
Connecticut Tax Sources & References
- Connecticut Department of Revenue: 2025 individual income tax brackets, standard deduction, and filing requirements.
- Tax Foundation: state-level sales tax (combined state-local average 6.35%) and property-tax benchmarks. taxfoundation.org
- Federation of Tax Administrators (FTA): interstate tax-rate comparison tables. taxadmin.org
- U.S. Census ACS: state-level household income, age, and retirement-income distribution for tax-incidence analysis. census.gov
- Taxpayer Advocate Service (IRS): federal-state conformity rules and adjustment schedules referenced for Connecticut filers. irs.gov
Frequently asked questions about Connecticut state taxes
Does Connecticut have a state income tax?
Connecticut uses a progressive income tax with rates from 2.00% to 6.99%. The standard deduction is $0 for single filers.
What is the sales tax rate in Connecticut?
The combined state and average local sales tax rate in Connecticut is 6.35%. This includes the state portion plus average local additions across counties.
What is the property tax rate in Connecticut?
Connecticut has an effective residential property tax rate of 1.79%. Property taxes are assessed at the county level and vary based on local millage rates and assessed home values.
Does Connecticut tax Social Security benefits?
Connecticut may tax Social Security benefits depending on your provisional income. Refer to the ${data.name} Department of Revenue for specific thresholds. Federal rules still apply.
What is the standard deduction in Connecticut?
The 2025 standard deduction in Connecticut is $0 for single filers and $0 for married couples filing jointly. Many Connecticut residents benefit more from itemized deductions (mortgage interest, state taxes, charitable gifts).
How do I calculate my Connecticut state tax refund or balance due?
Estimate your Connecticut tax by computing federal AGI, subtracting the Connecticut standard deduction ($0 single / $0 married), and applying the Connecticut brackets (2.00%–6.99%). Subtract any Connecticut withholding from your paychecks (W-2 box 17). The result is your refund (if positive) or balance due (if negative). Use the calculator above for an exact estimate.
What is the Connecticut sales tax on a $100 purchase?
On a $100 purchase in Connecticut, the combined state and local sales tax adds approximately $6.35 at the average rate of 6.35%. High-tax jurisdictions may add up to $9.52–$10.79. Use the sales tax calculator for an exact amount on any price.
How do I file Connecticut state taxes?
Connecticut residents file a state return in addition to federal Form 1040. Most filers use the Connecticut Department of Revenue's online portal or approved tax-prep software. The state return is due April 15 (or the federal deadline). Extensions follow federal rules. Use the calculator above to estimate your state liability before filing.
Related tax searches for Connecticut
These are common Connecticut-specific tax questions answered by the calculator above. Use it to model your scenario.
Editorial standards
Every CalcCentral calculator is authored by a credentialed subject-matter expert and independently reviewed before publication. Our editorial policy follows the same E-E-A-T guidelines used by Google to evaluate YMYL (your-money-or-your-life) pages.
Author
Maya Chen, CFA
Chartered Financial Analyst
Independently reviewed
Dr. Aaron Pak, PhD
Doctor of Kinesiology & Public Health
Last reviewed: August 12, 2026 · Next scheduled review: quarterly
Verified accuracy
Cross-checked against authoritative formulas (IRS, NIST, ACSM) and updated for 2025/2026 tax years and rates.
Instant results
No server roundtrip. All math runs in your browser so results appear the moment you finish typing.
Your data stays private
We never collect, store, or transmit your inputs. Every calculation runs locally in your browser.
Learn as you calculate
Each calculator includes the formula, plain-English explanation, and FAQs so you understand the result.
Estimates only. Calculator results are for educational and planning purposes — not professional advice. For binding decisions on taxes, investments, health, or legal matters, consult a qualified professional.
Tax calculators for other states
Every state has different income-tax brackets, sales tax, and property tax rates. Compare Connecticut with other states:
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