Quarterly Estimated Tax Calculator — Connecticut (2026)
If you earn income in Connecticut without withholding — freelancing, contracting, rentals, dividends — the IRS expects payment four times a year, not once. This calculator turns your expected 2026 net profit into a per-quarter number covering self-employment tax, federal income tax and Connecticut state tax. Connecticut uses a progressive income tax with 7 brackets running from 2.00% up to 6.99%, applied after a state standard deduction of $0.
Connecticut Quarterly Tax Calculator
Gross 1099 income minus business expenses.
2026 due dates and safe harbor
Federal estimated payments are due April 15, June 15, September 15 of 2026 and January 15 of 2027. You avoid penalties by paying either 90% of the current year's liability or 100% of last year's (110% if prior-year AGI exceeded $150,000) — the safe-harbor rule.
Connecticut runs its own estimated-payment schedule that usually mirrors the federal dates. On $90,000 of net profit the Connecticut portion alone is about $963 per quarter.
Underpayment penalties
The IRS charges interest-style penalties per quarter you fall short, currently around 7–8% annualized. Paying late in the year does not fix an early-quarter shortfall unless you use the annualized income method on Form 2210.
Irregular income is common in insurance work around Hartford: if Q1 is slow and Q4 is huge, the annualized method usually beats four equal payments.
Paying as a Connecticut taxpayer
Pay federally through IRS Direct Pay or EFTPS, and Connecticut through the state revenue department's online portal — keep confirmation numbers for both.
Connecticut has no separate city or county income tax, so the state figure above is the full sub-federal income tax you pay.
Local and payroll taxes Connecticut adds on top
Paid Family and Medical Leave takes 0.5% of wages up to the Social Security wage base. That deduction sits outside the federal and state income tax lines, so build it into your own budget on top of the numbers above.
Connecticut has no separate city or county income tax, so the state figure above is the full sub-federal income tax you pay.
Nobody withholds these for you when you are self-employed in Connecticut. Local wage taxes, city business licences and gross-receipts style levies are yours to register for and remit alongside your quarterly federal and state estimates.
Working across a state line from Connecticut
Connecticut has no income-tax reciprocity agreements, so if you live here and work across a state line you generally file a nonresident return in the work state and claim a credit at home to avoid double taxation.
Remote and hybrid work complicates this further: most states tax income where the work is physically performed, so a Hartford resident spending part of the year at a client site in Massachusetts may owe a nonresident return there. Keep a day-count log if you split time between states.
The rest of your Connecticut tax bill
Connecticut charges a 6.35% state sales tax, homeowners pay an average effective property tax of 1.79% of market value, and the minimum wage in force during 2026 is $16.94 an hour.
No local sales tax, so 6.35% is the rate statewide.
Income tax is only one part of a state's take. Connecticut recovers revenue through sales and property tax as well, which is why headline income tax rates alone are a poor guide to how far a salary really goes. Connecticut phases out tax on Social Security, pensions and annuities below income thresholds ($75,000 single).
Connecticut vs Massachusetts on the same salary
On a $90,000 salary, a single filer keeps about $67,945 a year in Connecticut against roughly $67,645 in Massachusetts — a difference of $300, or $25 a month.
Effective combined rates are 24.5% in Connecticut and 24.8% in Massachusetts. Set that gap against living costs: index 116 here versus 148 there, with property tax at 1.79% and 1.14% respectively.
Connecticut income tax brackets 2026 (single filer)
| Taxable income | Rate |
|---|---|
| $0 – $10,000 | 2.00% |
| $10,000 – $50,000 | 4.50% |
| $50,000 – $100,000 | 5.50% |
| $100,000 – $200,000 | 6.00% |
| $200,000 – $250,000 | 6.50% |
| $250,000 – $500,000 | 6.90% |
| $500,000 and up | 6.99% |