Rent vs Buy in Boston
The Verdict
Zillow's July 2026 release puts the ZHVI for the Boston, MA metro at $742,341 as of 2026-07-31, and the ZORI index at $3,165. Rounded for presentation, this report models a $742,000 purchase against a $3,160 monthly rent — a price-to-rent ratio of 19.6, the ninth-highest of the thirty-one metros in this tier. Appreciation is modelled at 3.2% a year, the FHFA all-transactions house price index over the year to 2026Q2 for Boston, MA (MSAD); the 5-year annualised figure is 6.9%, and the note under the appreciation stat names which one the engine was given. Run through the engine at this report's stated basis — 6.1% on a 30-year fixed, 20% down, 8% selling costs, a 7% return on the renter's portfolio and the $3,160 blended rent as the comparable — there is no month inside thirty years in which the buy path passes the rent path. At seven years the renter is ahead by $105K; at ten years, by $124K. That is an answer rather than a missing number, and it is the honest headline for this market today. Boston is the second-most-expensive market in this tier at $742,000, behind Honolulu, and the upfront cash requirement is $170,660. That sum invested at 7% is what the buy path has to beat, and at 3.2% appreciation and a price-to-rent ratio of 19.6 it does not.
Break-Even Analysis
Break-even here is a month, not a rule of thumb. The engine runs both paths side by side and reports the first month in which the buyer's net worth — the projected value of the home, less the loan balance, less what it would cost to sell in that month — passes the renter's. The renter's side is the buyer's entire upfront cash invested at 7% and then fed or drained every month by the difference between the two paths' running costs, so a month in which owning costs less than renting is a month the renter's portfolio stops growing as fast. At this basis that month never arrives inside thirty years. The sweep below moves one input at a time — a single percentage point, or half a point on the rate — and only one of the six produces a crossing at all: a point more rent growth brings one at month 327. Run instead on the 5-year annualised FHFA rate of 6.9% and a crossing appears at month 39. Hold the home value flat for thirty years and there is no crossing at all — the buy case here needs price growth, not just principal. Scale is what makes this different from the other markets here with no crossing. The renter is ahead by $104,814 at seven years and $124,170 at ten, and on the engine's trajectory the gap is still widening at year ten rather than closing.
The Two Paths at 7 and 10 Years
The three lines in the tables below are engine output at the basis above, not illustrations. Buyer equity is the projected home value less the loan balance less the cost of selling in that year. The renter portfolio is the buyer's entire upfront cash — the $148,400 down payment plus $22,260 of closing costs, less the renter's own $3,000 move-in cost — invested at 7% and then fed or drained every month by the difference between the two paths' costs. Transaction and carrying costs are every dollar that never became equity: closing costs, interest, property tax, insurance, maintenance and the exit fee combined. At seven years that is $318K of buyer equity against $423K in the renter's portfolio, with $447K spent on costs that bought no equity at all. By ten years the two sides read $437K and $561K. The gap is $105K at seven years and $124K at ten, still widening in the renter's favour. Both tables assume the home is sold at the horizon, because a comparison that never charges the exit cost flatters the buy path by the full 8%: $74,003 at year seven in this market.
What Moves the Answer
Every row of the sensitivity table above is a re-run of the whole thirty-year simulation with one input changed and everything else held at the basis. There is no crossing month to move, so the useful measure is the seven-year gap, which currently stands at $105K in the renter's favour. A percentage point more appreciation makes it $49K to the renter; a percentage point less appreciation makes it $157K to the renter; half a point on the mortgage rate makes it $130K to the renter; a point more on the renter's return makes it $129K to the renter. Rate and appreciation move the answer through different channels, which is worth keeping separate: the rate changes the monthly payment from month one — half a point is $194 a month on this loan — while appreciation changes only the equity line and only over time. Rent growth is modelled at 3% a year and applied once a year at renewal rather than continuously, which is why a point on it moves the answer less than a point on appreciation does. The renter's 7% return is the assumption most worth arguing with: it is a nominal, pre-tax, fully-invested figure, and every point you take off it moves the answer toward buying.
The Cost Picture
At $742,000 with 20% down, the loan is $593,600 and principal and interest come to $3,597 a month at 6.1%. Adding property tax at 1.10% and insurance at 0.3% of value puts the full PITI at $4,450 in month one and $4,650 by year seven. That climb is the annual step: property tax, insurance and maintenance are recomputed at each year boundary on the projected value of the home rather than held at the price paid, so they rise with the market the equity line is riding. Over seven years the buy path pays $241,607 in interest, $62,921 in property tax, $17,161 in insurance and $28,601 in maintenance, and $74,003 to sell. Only Honolulu carries a larger seven-year interest bill in this tier, and the tax line is larger here than anywhere except Hartford. The 1.10% rate is not a statutory rate: it is the ACS 2023 five-year median real-estate tax bill for Boston-Cambridge-Newton, MA-NH Metro Area — $6,696 — divided by that survey's median home value of $610,900. Across the 393 metro areas in the same ACS file the effective rate runs from 0.17% (Kahului-Wailuku, HI) to 2.64% (Rochester, NY), with a median of 0.82% and a tenth-to-ninetieth-percentile band of 0.49% to 1.69%. Boston sits above the median and inside the middle eighty percent.
Run Your Own Numbers
This report models exactly one scenario: the metro median home, the metro blended rent, 20% down, a 30-year fixed at 6.1%, 8% selling costs and a 7% return on the renter's portfolio. None of those will be precisely your numbers, and the report is more useful as a starting point than as a verdict. The calculator runs the same engine on whatever you give it — your actual price and rent, a different down payment, an association fee the metro median does not include, a shorter horizon, a different return assumption. The methodology article documents every formula behind the figures on this page, including how the renter's portfolio is funded month by month, how property tax steps at each year boundary, and why the exit cost is charged against the projected value at sale. Two inputs are worth changing before any of the others. The rent, because the $3,160 used here is a blended all-homes index across the whole metro and not the unit you would actually sign for. And the horizon, because there is no holding period inside thirty years at which this market's medians favour buying, so the only thing that can change the answer is a number that is yours rather than the metro's.
7-Year Scenario Comparison
10-Year Scenario Comparison
Sensitivity Analysis
Local Risk Factors
Frequently Asked Questions
- Zillow Research. ZHVI (all homes, smoothed, seasonally adjusted) and ZORI (all homes, smoothed) for the Boston, MA metro, July 2026 release, observation dated 2026-07-31.[zillow.com/research ↗]
- Federal Housing Finance Agency. House Price Index, all-transactions, metropolitan, Boston, MA (MSAD) (CBSA 14454), through 2026Q2.[fhfa.gov ↗]
- U.S. Census Bureau. American Community Survey 5-Year Estimates 2023 (2019–2023), Boston-Cambridge-Newton, MA-NH Metro Area (CBSA 14460): median gross rent B25064, median home value B25077, median real estate taxes B25103.[census.gov ↗]
- U.S. Census Bureau. American Community Survey 5-Year Estimates 2023, effective property tax rates across all 393 metropolitan statistical areas (B25103 over B25077).[census.gov ↗]
- Federal Reserve Bank of St. Louis. FRED: 30-Year Fixed Rate Mortgage Average in the United States (MORTGAGE30US).[fred.stlouisfed.org ↗]