Boston Mortgage Affordability Calculator

How much house can you afford in Boston? Estimate your maximum price with debt-to-income limits, local property tax, insurance and HOA fees.

Your numbers

Result

The Reasoning

Your explanation will appear here.

Rates, thresholds, fees and minimums used here change over time. Figures were checked on 09/27/2026 — confirm current numbers with the official sources listed on this page.

What this calculator does

This calculator estimates the highest home price you can support in Boston using the two debt-to-income limits lenders commonly use: housing costs as a share of gross income (front-end) and all debts as a share of gross income (back-end). Unlike a basic affordability tool, it includes Boston's property tax, home insurance and HOA or condo fees, which change the answer a lot from city to city.

Boston's housing mixes triple-deckers, brownstones and newer towers. Neighborhoods include Back Bay, the South End, Jamaica Plain, Dorchester, East Boston, Charlestown and Roslindale. Many leases start September 1 because of the large student population.

How to use it

  1. Enter gross income for everyone on the loan and your monthly debt payments.
  2. Enter the cash you have for a down payment.
  3. Set the mortgage rate and term.
  4. Adjust the 28% / 36% limits if your lender uses different ratios (some programs allow up to 43% or more on the back end).
  5. Check the local property tax, insurance and HOA defaults and replace them with numbers from listings.

The formula

Maximum housing payment = the lower of (income ÷ 12 × front-end %) and (income ÷ 12 × back-end % − other debts). The price is solved so that principal and interest on (price − down payment), plus property tax and insurance as a percentage of price, plus HOA dues, equals that payment.

Worked example for Boston

Household income $147,000, $400 of other debts, default down payment and local costs:

ItemMonthly
Gross monthly income$12,250
Existing debt payments-$400
Principal and interest$2,319
Property tax at 1.24% a year$462
Home insurance at 0.4% a year$149
HOA / condo fees$500
Total housing payment$3,430

Estimated maximum home price: $446,923. Loan of $366,923 with $80,000 down; total housing payment $3,430 a month.

What limits buying power in Boston

Boston's FY2026 residential tax rate is $12.40 per $1,000 of assessed value. Owner-occupants can claim the residential exemption, worth up to $4,353.74 in FY2026, which removes a flat amount of value from the bill.

Condo associations and HOAs add monthly dues that count toward the housing payment exactly like property tax.

Common mistakes and tips

  • Using take-home pay instead of gross income — lenders use gross.
  • Leaving out HOA or condo fees, which count just like property tax.
  • Emptying savings for the down payment — lenders and co-op boards often want reserves.
  • Assuming the maximum is comfortable; a price below it leaves room for repairs and rate changes.
  • Forgetting PMI when putting down less than 20% on a conventional loan.

Frequently asked questions

How much house can I afford in Boston?

With the default inputs on this page, the estimate is $446,923. Your result depends mostly on income, debts, down payment and the mortgage rate.

What is the 28/36 rule?

A common guideline: housing costs up to 28% of gross income and total debt payments up to 36%. Many loan programs allow higher ratios with strong credit or reserves.

Why does property tax matter so much in Boston?

Property tax is paid every month through escrow, so a higher rate leaves less room for the loan itself. Boston's effective rate is set in the defaults and explained in the property tax calculator.

Does this replace a lender pre-approval?

No. A lender reviews credit, income documents and the specific loan program. Use this estimate to plan before talking to lenders.

Sources

  1. CFPB — Debt-to-income ratio
  2. Fannie Mae Selling Guide — debt-to-income ratios
  3. Massachusetts Department of Revenue
  4. City of Boston Assessing Department

Disclaimer

This calculator provides estimates for educational purposes only and is not financial, tax, legal, real estate, or insurance advice. Consult a licensed professional before making decisions.