Connecticut Tax Calculator Connecticut state income tax rate for current tax year: 6.99% The Connecticut Tax Calculator Start Over Select a Tax Year 2021 2022 2023 2024 2025* Select Your Filing Status Single Head of Household Married Filing Joint Married Filing Separately Surviving Spouse Select Your State Deduction Method Standard Itemized Enter est. Annual State Income $ Enter est. Annual Deductions, Adjustments Do not enter your Standerdized Deduction Amount $ Total Estimated Annual Deductions $0 Annual Taxable State Income $0 Est. Annual State Income Taxes $0 Enter est. Annual State Tax Credits, Withholdings $ Est. State Taxes Due $0 Disclaimer: eFile.com makes no warranty as to the accuracy of the results of this estimator or calculator tool. The results are estimates and for informational purposes only, and should not be relied on for tax advice.* This tax year will be updated as the data becomes available. TurboTax® is a registered trademark of Intuit, Inc. H&R Block® is a registered trademark of HRB Innovations, Inc.