1. Fair market value vs assessed value
Under CGS §12-63, real property is assessed at 70% of fair market value as of the assessment date (commonly October 1). A $800,000 market value becomes a $560,000 assessment before exemptions. Towns revalue on a cycle; between revaluations, the listed assessment may lag or lead the price you see on Zillow or a purchase contract.
2. What a mill rate is
One mill equals $1 of tax per $1,000 of assessed value. A mill rate of 25 means $25 per $1,000 assessed. On a $560,000 assessment that is $14,000 of municipal tax before special districts. Mill rates are local budget tools: two towns can have different mills and different typical home prices, so comparing mills without a fixed price can mislead.
3. The municipal estimate formula
This site’s calculator and town pages use:
annual tax = (price × 0.70 × mill rate) ÷ 1,000
Monthly ≈ annual ÷ 12. Effective rate = annual tax ÷ market price, which is approximately mill rate × 0.70 ÷ 1,000 when no exemptions or extra districts apply. Example: 20 mills → about 1.40% effective on market value.
4. What the municipal rate does not include
- Fire and special taxing districts — common in parts of Connecticut; they add mills.
- Exemptions — veterans, elderly, disability, and other local reductions.
- Motor vehicles — separate mill rate, capped at 32.46 mills.
- Assessor judgment — your grand-list value may not equal 70% of your offer price.
5. How to use this on a house hunt
Pick one price (for example $1.6M) and compare towns in the calculator or on a compare page. That isolates the mill-rate effect. Then open each town page, note the effective rate, and verify with the assessor before you write an offer. If the assessment looks high relative to sales, read the appeal overview.