Rent vs. Buy Calculator for the Bay Area
Compare what it really costs to buy or keep renting anywhere in San Mateo County, San Francisco or Santa Clara County. It accounts for local transfer taxes, Prop 13 property tax, closing and selling costs, and what your down payment could earn if you invested it instead.
How to use the rent vs. buy calculator
Follow these steps from top to bottom. Each box already has a sensible starting number, so you only need to change what you know.
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Choose single family home or condo / townhome
Use the switch at the top of the form. It sets typical prices, rents, HOA dues and insurance for that kind of home.Where to find it: the listing says the property type. Townhomes are listed with condos.
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Pick the city
This sets the local transfer tax, property tax rate, a typical price, a typical rent and the city's home value growth.Where to find it: the city in the home's address.
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Enter the home price
Start with the price of a home you like, or keep the city's typical price to explore.Where to find it: the listing price on this site's home search, Zillow or Redfin. For a better number, ask Joseph for a free comparison of recent sales.
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Enter your down payment
The share of the price you pay in cash. Putting 20% or more down avoids mortgage insurance.Where to find it: your savings you are willing to use, and your lender's preapproval, which says what your loan allows.
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Add HOA dues, if any
Monthly dues for condos, townhomes and some houses in planned communities. Most houses have none, so leave it at $0.Where to find it: the listing details (HOA fee) or the HOA's disclosure documents.
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Enter your mortgage rate
The interest rate on your loan. The box starts at this week's national average.Where to find it: a rate quote from your lender (the Loan Estimate shows it on page 1). Jumbo loans can price differently.
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Choose how long you plan to stay
Buying works better the longer you stay, because buying and selling costs are spread over more years.Where to find it: your own plans: job, schools, family. Your best honest guess is fine.
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Enter the rent for a similar home
What you would pay to rent a home like the one you would buy. It is filled in with a typical rent for the city.Where to find it: your current lease, or rentals with the same bedrooms in the same area on Zillow, Zumper or Craigslist.
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Set the yearly rent increase
How much rent goes up each year. 3% is the default.Where to find it: your past rent increases. California's rent cap limits increases on many apartments to 5% plus inflation, at most 10% a year; many houses and condos owned by individuals are exempt.
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Check the home value growth
Filled in with the city's average yearly growth over the last 10 years (2% for condos). Lower it if you want to be cautious.Where to find it: the note under the box shows the city's 10 year average.
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Say what you would do with the money you save by renting
Be honest. Most people bank the extra money rather than invest every dollar.Where to find it: think about what you do today with money left over each month.
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Enter what your investments earn
Used for money you invest instead of buying. 6% is a middle of the road long run figure for a stock and bond mix.Where to find it: your brokerage or retirement account statements. Use a lower number if you keep cash.
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Optional: fine tune the details
Open Owning costs, Buying and selling costs, and Taxes to adjust property tax, parcel taxes, insurance, maintenance and your household income, which sets your tax brackets. The defaults work for most people.Where to find it: property tax and parcel taxes: the home's tax bill on the county tax collector's website or the listing's tax history. Insurance: a quote from your agent. Household income and tax bracket: last year's tax return or your CPA.
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Read your results
The top box says whether buying or renting comes out ahead and by how much. Below it, see when buying pulls ahead, the rent you would pay versus the equity you would build, and a year by year chart.Where to find it: everything updates as you type, so try a few different numbers.
Result
Where your money goes
Rent you would pay
Goes to your landlord. Builds $0 in home equity, and rent usually rises every year.
Owning costs you would not get back
What owning builds that renting does not: home equity of
Buying vs. renting by how long you stay
First year, average per month
When you sell
How this calculator works and where the numbers come from
- How it works. Like the New York Times and NerdWallet rent vs. buy calculators, this compares your net worth in each case. If you rent, the money you would have spent on the down payment and closing costs is invested, and any month where owning costs more than renting adds to your savings. If you buy, you keep the home's value after selling costs, loan payoff and any tax on the profit, plus whatever you saved in months when renting would have cost more.
- What renters do with the savings. Owning usually costs more per month than renting at first, so a renter has money left over. The New York Times calculator assumes a renter invests every dollar of it, every month, for decades. Most people do not, so by default this calculator assumes the renter invests the down payment and keeps the monthly savings in the bank, earning nothing. Choose "Invest all of it" to see the strict version. Either way, a mortgage payment builds equity automatically, and rent does not.
- Single family vs. condo. Condo and townhome defaults use $600 a month in HOA dues, $900 a year for condo insurance (the HOA insures the building), and maintenance of 0.5% of value a year. Peninsula condos have gained value much more slowly than houses; the San Mateo condo median fell about 7% from early 2024 to early 2026, so condo growth defaults to a conservative 2% a year. Single family homes can have HOA dues too, so enter them if the home has one.
- Local rules built in. Property tax follows Prop 13: your assessed value starts at the purchase price and rises at most 2% a year, no matter how fast values grow. Default rates are about 1.18% in San Mateo County and San Francisco (1.1827% for 2025 to 2026) and 1.2% in Santa Clara County; your parcel may differ. San Mateo and Santa Clara counties charge a transfer tax of $1.10 per $1,000, paid by the seller. City transfer taxes, split between buyer and seller: City of San Mateo 0.5% (1.5% at $10 million and up), Hillsborough $0.30 per $1,000, Palo Alto $3.30 per $1,000, Mountain View $3.30 per $1,000 ($15 per $1,000 over $6 million), and San Jose $3.30 per $1,000 plus Measure E on sales of about $2.3 million and up (0.75%, 1% over $5 million, 1.5% at $10 million and up). San Francisco has its own tax, usually paid by the seller: 0.5% up to $250,000, 0.68% under $1 million, 0.75% under $5 million, 2.25% under $10 million, 5.5% under $25 million and 6% above. Other cities have no city transfer tax.
- Home price. The default price is the median sale price over the past year on Zillow (recently sold homes, which include MLS sales) for a 3 bedroom house, or a 2+ bedroom condo or townhome, in the city you pick. It changes with the city until you type your own price. Where a city had too few condo sales, a nearby city is used.
- Default values. Mortgage rate is the Freddie Mac average 30 year fixed rate for Oct 29, 2026 (7.24%); larger jumbo loans can price differently. Suggested rent is the median asking rent on Zillow on Oct 31, 2026, which includes MLS listings: for a single family home, 3 bedroom houses in that city (3+ or 4+ bedroom houses where fewer than three 3 bedroom houses were listed); for a condo or townhome, units with 2 or more bedrooms. Where a city had too few rentals, the note under the rent box says so: it uses a nearby city, or for condos estimates rent at 5.4% of the price per year, the median rent to price ratio for condos in cities with enough listings. Bigger or newer homes rent for more, so enter the rent for a home like the one you would buy. Tax figures use 2026 federal brackets and standard deduction ($32,200 joint, $16,100 single), the 2026 SALT cap of $40,400, which shrinks by 30% of income above $505,000 down to $10,000, interest on up to $750,000 of mortgage debt federally and $1 million for California, and California's brackets and standard deduction of about $11,000 joint. Household income defaults to the income lenders usually want for this home (housing costs at 28% of gross income); enter the real number for an accurate result. Tax savings count only deductions beyond what you would claim without the home.
- Home value growth by city. For houses, the default growth rate is each city's average yearly home value growth from late 2015 to late 2025, from NeighborhoodScout, and is shown under the growth box. Brisbane, Colma, Portola Valley and Monte Sereno have no published figure, so 4% is used. Past growth does not guarantee future growth, and values can fall. Rent paid builds no ownership; home equity shown is value minus loan balance, before selling costs.
- Taxes when you sell or cash out. Profit on the home above the $250,000 single or $500,000 joint exclusion is taxed at your long term capital gains rate. The exclusion requires living in the home 2 of the last 5 years, so stays under 2 years get no exclusion, and a sale within 1 year is taxed at ordinary income rates. The renter's investment gains are also taxed at the long term rate at the end, so both sides are compared after tax. If home values fall, property tax follows the lower market value (Prop 8) instead of rising 2% a year.
- Simplifications. Year 1 monthly costs are averages over the first 12 months. Investment returns are steady every year, while real markets move up and down. Selling costs, rates and tax rules are assumed to stay the same for the whole stay.
- An estimate, not advice. Results depend heavily on home value growth and investment returns, which nobody can predict. Your actual property tax depends on the parcel. Talk with your lender and tax advisor before you decide.