Connecticut Mortgage Calculator (CT)
Estimate your total Connecticut monthly payment — principal, interest, property tax and insurance — using your town's mill rate.
A Connecticut monthly mortgage payment is the loan's principal and interest plus property tax and insurance. CT property tax is the assessed value — 70% of market value — times the town's mill rate divided by 1,000. Because mill rates vary widely by town, the tax portion depends heavily on where the home is.
⚠️ Double-check important results. This is an educational estimate, not professional advice — and where it uses a rate, bracket or fee, those change over time. Verify anything you'll rely on, especially in legal, financial, tax or medical matters, and read our full disclaimer. Think a result is wrong? Tell us so we can fix it.
How to Use This Calculator
Enter the home price and your down payment; the difference is the loan amount. Add your mortgage interest rate and the loan term in years. Then enter your Connecticut town's mill rate — this is the number that makes a CT payment different from a generic one, and it varies enormously between towns.
Add your annual home insurance and the calculator returns the full monthly payment broken into principal and interest, property tax and insurance. The interest rate is the one you have been quoted; this tool does not fetch live market rates.
How the Calculation Works
The principal and interest use the standard amortization formula, where r is the monthly interest rate and n is the number of monthly payments. This spreads the loan into equal payments over the term.
Connecticut property tax works differently from a flat percentage. Towns assess homes at 70% of market value, then apply a mill rate — dollars of tax per $1,000 of assessed value. So the annual tax is the home price times 0.70 times the mill rate divided by 1,000. A 30-mill town taxes a $400,000 home on its $280,000 assessment.
P&I = L × r(1+r)ⁿ ÷ ((1+r)ⁿ − 1); CT tax = price × 0.70 × mill ÷ 1000
Worked Example
On a $400,000 home with $80,000 down, the loan is $320,000. At 6.5% over 30 years, the principal and interest come to about $2,022.62 a month.
The property tax: the assessed value is 400,000 × 0.70 = $280,000, and at a 30-mill rate the annual tax is 280,000 × 30 ÷ 1,000 = $8,400, or $700 a month. Adding $100 a month for insurance gives a total of about $2,822.62 a month.
Assumptions, Limitations and Rate Source
Connecticut assesses property at 70% of fair market value, which this calculator uses. Mill rates are set by each municipality and change annually, and they range from roughly 11 to over 70 mills across the state, so the tax portion is only as accurate as the mill rate you enter.
The interest rate is the figure you enter, not a live market rate. This estimate excludes PMI, HOA dues and any special district assessments.
- Uses CT's 70% assessment ratio; confirm your town's ratio if it differs
- Mill rates vary from about 11 to over 70 by town and change yearly
- Interest rate is user-entered — not a live market quote
- Excludes PMI, HOA fees and special assessments
Rate source. The default value used above (30 mills (CT town average)) comes from Connecticut Office of Policy & Management — Municipal Mill Rates. Rates like this change over time, so the field in the calculator is editable — overwrite it if it has changed.
Last verified 2026-07-30
Who Uses a Connecticut Mortgage Calculator
Connecticut homebuyers and homeowners use this to estimate a monthly payment that includes the town's property tax, which varies widely by mill rate across the state. Enter the price, loan terms, and your town's mill rate before house-hunting or refinancing to see the true monthly cost, not just principal and interest. It is built for Connecticut's high, town-specific property taxes that generic calculators miss.
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Open calculator →Frequently Asked Questions
How is property tax calculated in Connecticut?
Connecticut assesses homes at 70% of market value, then applies the town's mill rate — tax per $1,000 of assessed value. A $400,000 home in a 30-mill town is taxed on $280,000, giving $8,400 a year.
What is a mill rate?
A mill rate is the property tax charged per $1,000 of assessed value. A rate of 30 mills means $30 of tax for every $1,000 assessed. Each Connecticut town sets and updates its own.
Why are Connecticut mortgage payments higher than elsewhere?
Because Connecticut has some of the highest effective property taxes in the country. The tax portion of a CT payment can rival a chunk of the principal and interest, especially in high-mill-rate towns.
Does this calculator use current mortgage rates?
No. You enter the interest rate you have been quoted. It does not pull live market rates, so you control the rate assumption and can compare different quotes.
Where do I find my town's mill rate?
The Connecticut Office of Policy & Management publishes every municipality's mill rate each year. Your town assessor's office also lists it. Enter that figure for an accurate tax estimate.
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