Mill rate source: CT Office of Policy and Management · FY 2025–2026 · Assessment ratio: 70% per CT state law
These estimates use Connecticut's 70% assessment ratio and official FY 2025–2026 mill rates. Actual taxes depend on your assessor's valuation of the completed project, applicable exemptions, and any special district overlays. Construction cost is estimated from regional CT averages if not entered manually. Always verify with your local town assessor before making financial decisions.
Connecticut assesses all property at 70% of market value by state law. Know Your Build estimates the value your project adds, then applies your town's real mill rate from the CT Office of Policy and Management.
Annual tax = (assessed ÷ 1,000) × mill rate
Mill rates are updated annually. The FY 2025–2026 rates are currently in effect for all 169 Connecticut municipalities.
800 sq ft addition added
Est. build cost: ~$260,000
Est. value added: ~$195,000
New home value: $595,000
Assessed at 70%: $416,500
Hebron mill rate: 36.85
Current taxes: $10,318/yr
New taxes: $15,348/yr
Tax increase: ~$5,030/yr · $419/mo