Connecticut Income Tax Calculator - 2025 CT State Tax

A Connecticut income tax calculator estimates the state income tax you owe for the year from your gross income and filing status, using Connecticut's progressive 2% to 6.99% rate schedule. The estimate is annual, so it shows the total you would owe on a return rather than the amount taken from each paycheck.

• • Year-end planning: See your total Connecticut liability before you file the CT-1040.
• • Compare filing statuses: Check how married joint or head-of-household brackets change the bill versus single.
• • Model a raise or bonus: Watch how much of extra income stays after Connecticut tax.

Connecticut does not start from taxable income the way the federal return does. It builds its tax on Connecticut adjusted gross income, which begins from federal adjusted gross income, then applies its own personal exemption rather than the federal standard deduction. For the per-paycheck view that splits this same state math into each period, the Connecticut paycheck calculator turns annual Connecticut tax into estimated take-home pay.

Because Connecticut reconciles to federal adjusted gross income, a move that lowers your federal taxable income usually lowers your Connecticut tax too. The federal income tax calculator shows the parallel federal math so you can see both layers together.

The tool treats your entered income as Connecticut adjusted gross income, subtracts the Connecticut personal exemption (with the income-based phase-out), and applies the 2% to 6.99% schedule. For most wage earners the starting point is simply total gross wages.

• Connecticut AGI: Begins from federal adjusted gross income; for a wage-only employee this is essentially total gross wages before any state-specific subtraction.
• Personal exemption: Starts at $15,000 single, $24,000 married, or $19,000 head of household, then phases out as income rises.
• Other Connecticut subtractions: Retirement and other CT-1040 subtractions that lower Connecticut taxable income directly.
• Connecticut tax: The progressive 2% to 6.99% schedule applied to the positive Connecticut taxable income.

The result is Connecticut tax; the effective rate is that tax divided by gross income, and the marginal rate is the top bracket your taxable income reaches. A single filer with $65,000 owes roughly $2,825, an effective rate near 4.3% and a marginal rate of 5.5%, because the personal exemption has fully phased out by that income.

Comparing Connecticut's brackets with the federal schedule shows how much of a raise or bonus actually reaches your bank account. Running the numbers before you accept a job offer, adjust withholding, or plan a bonus helps you avoid a surprise when the Connecticut return is filed. For the federal bracket and standard-deduction steps that feed the state math, the federal income tax calculator walks through the same federal base.

A worked example shows why the personal exemption matters. A single filer with $30,000 of Connecticut adjusted gross income keeps most of the personal exemption, so taxable income lands near $17,000 and Connecticut tax is only about $660. At $65,000 the exemption has fully phased out, taxable income is the full $65,000, and tax is roughly $2,825. The same calculator inputs make the difference visible in seconds, which is why a Connecticut income tax estimate is more useful than reading the bracket table by hand.

According to the Connecticut Department of Revenue Services, Connecticut imposes a progressive individual income tax with rates from 2% to 6.99% for the 2025 tax year, built on Connecticut adjusted gross income.

According to the IRS, federal adjusted gross income is the starting point that states such as Connecticut build their state taxable income from.

A few terms decide almost everything about your Connecticut result.

The per-paycheck version and the annual return are two views of the same Connecticut math. The Connecticut paycheck calculator shows the withholding taken from each check, while this tool shows the total annual liability on the return.

You only need your gross income and filing status to get a close estimate. The connecticut income tax calculator reads those two inputs first, then layers the personal exemption and any other subtractions on top.

1. 1 Enter your annual gross income: Type your Connecticut gross wages as they appear before Connecticut subtractions.
2. 2 Pick your filing status: Select the status that matches your Connecticut return; it sets the bracket thresholds and the personal exemption phase-out range.
3. 3 Add other Connecticut subtractions: Enter any retirement or other CT-1040 subtractions you qualify for.
4. 4 Enter dependents if a credit applies: Add the number of dependents claimed on the Connecticut return.

A single filer with $65,000 gross income and no subtractions owes roughly $2,825 after the personal exemption has fully phased out.

If you track your gross income from an hourly or per-paycheck figure, the annual salary calculator converts it into the annual amount this tool needs.

An annual estimate helps with planning well before you file. The connecticut income tax calculator shows the dollar amount you owe on the return, which is different from the per-paycheck withholding a paycheck tool reports.

• • Clear state liability: You see the exact Connecticut tax from your income without reading the rate schedule by hand.
• • Filing-status comparison: Switching between single, married joint, and head of household shows the bracket and exemption difference immediately.
• • Raise and bonus what-ifs: You can see how much of extra income stays after Connecticut tax.

Because Connecticut reconciles to federal adjusted gross income, a change that lowers your federal taxable income usually lowers your Connecticut tax too. The gross to net calculator shows how federal and state tax together convert a salary into take-home pay, which is useful context before you decide how to file.

Planning a year ahead with a tax estimate also helps you set aside the right amount for the April payment and decide whether to adjust withholding after a bonus or a second job. Connecticut has no local income tax, so the state figure here is the only income tax layer for residents, apart from the federal return.

The marginal rate is the most useful number for planning the next dollar of income: only the slice above your current bracket is taxed at the higher rate, so a raise rarely costs as much as the top rate suggests.

Several inputs move the answer the most. The connecticut income tax calculator treats gross income as the base, so any input that lowers Connecticut taxable income also lowers the final bill.

• • This tool estimates the base Connecticut tax and excludes any non-resident allocation, part-year residency, itemized credits, and local withholding. Final liability is on the CT-1040.
• • The 2% to 6.99% schedule is current 2025 law; a future rate change would require updating the schedule used here.

Connecticut tax is only the state layer; the payroll tax calculator breaks out Social Security and Medicare separately from income tax. Because Connecticut has no local income tax, the 2% to 6.99% state rate is the only income tax layer for Connecticut residents.

According to the Connecticut DRS, the 2025 CT-1040 personal exemption phase-out thresholds and the high-income recapture determine the final Connecticut liability for the return.