property nerds®home valuevaluation 101
What’s it worth? Depends who’s asking.
Market value, list price, appraised value, assessed value and the online estimate are five different numbers, set by different people for different jobs. Here’s what each one measures, how far Prop 13 can pull your assessed value from the market, and which number decides things when you sell, buy or refinance.
The five valuesProp 13 gapWhich one mattersEvery tool
- silicon valley $/sq ft2.6×2012 median $382 → $992, last 12 months
- prop 13 ceiling1.32×most an assessed value can grow, 2012 to 2026
- sold over asking60%Silicon Valley sales, Jan 2024–Sep 2026
- base property tax1%of assessed value, before bonds and local charges
the five values
Five values, five jobs
Each one answers a different question, and only one of them is what a buyer pays.
| Value | Who sets it | What it measures | When it matters |
|---|---|---|---|
| Market value | Buyers and sellers, in the open market | The price a willing buyer and a willing seller agree to, with the home fairly marketed and neither under pressure. | When you sell or buy. A CMA and an appraisal are both estimates of it. |
| List price | The seller, with their agent | A pricing strategy, not a value. It can sit under market value to draw more buyers, or at it to screen out low offers. | The first number buyers see. 60% of Silicon Valley sales from January 2024 to September 2026 closed above it. |
| Appraised value | A licensed appraiser working for the buyer’s lender | An opinion of market value on one date, built mostly from closed comparable sales. | When a loan or a refinance depends on it. The lender lends on the lower of price and appraisal. |
| Assessed value | The county assessor | Your purchase price, grown at most 2% a year under Prop 13, plus permitted new construction. | Your property tax bill. It says little about what the home would sell for. |
| Online estimate | A computer model | A formula over public records and recent sales. It never sees the inside of the home. | A rough starting point. How close it lands depends on the data around your home. |
prop 13 gap
How far your assessed value trails the market
Pick your city and the year you bought, and enter what you paid. We grow that price two ways: by the most Prop 13 allows, and by your city’s median price per square foot since then.
Assessed value against market value
which one matters
Which number matters when
- SellingMarket value. The list price is a strategy for reaching it; comparable sales and the home itself set it.
- Buying with a loanMarket value and the appraised value. If the appraisal comes in under the price, the lender lends on the lower number and the buyer covers the gap in cash.
- Refinancing or a HELOCThe lender’s value, from an appraisal or its own model. It sets your loan-to-value, which can change your rate and whether you pay mortgage insurance.
- Property taxesAssessed value. It resets to the price when a home sells, so a buyer’s tax bill can be far higher than the seller’s was.
- Deciding whether to sellYour equity: market value minus what you owe, less what selling costs.
- Inheriting or gifting a homeBoth. Prop 19 changed when a parent-to-child transfer keeps the old assessed value, and the rules have conditions.
Prop 19 transfers, base-year transfers for owners 55 and over, and disaster relief all have conditions. We’re not tax advisors; check yours with the county assessor or a CPA.
go deeper
Every way we value a home
Two live tools and four guides, from the quick number to how an appraiser thinks.
live toolfor owners
Comps Finder
The eight closest sales to your home from the last 180 days, each adjusted to your size and lot, plus what’s for sale near it now.
live toolfor owners
Home Equity Check
Your purchase price at your city’s pace, minus what you owe, with what selling would cost and how much of the gain is taxed.
guidesellers and buyers
Comparative Market Analysis
How comps are picked and adjusted, with an example grid you can check line by line.
guidebuyers and sellers
Home Appraisal
How the appraisal works, what a gap costs and how often homes here sell over asking.
guideproperty nerds
The Three Approaches to Value
Sales comparison, cost and income: how appraisers value property, with calculators.
guideowners
Online Home Value Estimates
What a formula sees, what it misses and how wide one city’s prices run, live.
questions
Questions we hear
Is assessed value the same as market value?
No. In California, assessed value starts at your purchase price and can rise at most 2% a year under Prop 13, plus the value of permitted new construction. Market value follows what buyers pay. Silicon Valley’s median price per square foot is 2.6 times its 2012 level, while an assessed value from 2012 can have grown at most 1.32 times.
Why is my appraisal different from my online estimate?
An appraiser visits the home and adjusts a handful of closed comparable sales to it. An online estimate runs a formula over public records and can’t see condition, remodels or the layout.
Which value do buyers use?
Buyers pay market value, and in a competitive market they set it with their offers. 60% of Silicon Valley sales from January 2024 through September 2026 closed over the final list price.
Does a higher assessed value mean my home is worth more?
Not by itself. Two matching homes on the same street can have very different assessed values because they were bought in different years.
What is the list price for, then?
It’s a strategy for reaching market value: where to start the conversation with buyers. The comparable sales and the home itself decide where it ends.
How do you value a home?
We start with the closest recent sales, the way the Comps Finder does, adjust for size, lot, condition and updates after a walk-through, then check the homes a buyer would compare yours with today.
more to learn
Keep going
- What’s my home worth?An instant estimate, then a Property Nerd checks it against your street.
- Comps FinderThe eight closest sales to your home from the last 180 days, adjusted to your size and lot, live.
- Home Equity CheckYour purchase price at your city’s pace, minus what you owe, with what selling would cost.
- Comparative Market AnalysisHow an agent picks comps, adjusts them and turns them into a price range.
- Home AppraisalHow the appraisal works, what a gap costs and how often homes here sell over asking.
- The Three Approaches to ValueSales comparison, cost and income, with calculators for the last two.
- Online Home Value EstimatesWhat a formula sees and misses, with a live look at one city’s price spread.
- Then & Now CalculatorWhat a price from any year since 2012 is worth now, by city.
- How Much Over AskingThe Silicon Valley overbid in dollars, by year, city and price band.
- Property tax rates by cityRates for seven Silicon Valley cities, with year one on each median house.
- The supplemental tax billThe bill a buyer gets when the county reassesses the home at the price.
Estimates and examples for discussion only; not an appraisal, and not tax, legal or lending advice. Sales data: MLS via IDX, deemed reliable but not guaranteed. Equal Housing Opportunity.
talk to a property nerd
Want the number that counts?
We’ll pull the closest sales to your home, walk through it with you and give you a price range you can plan around. Commissions are negotiable, and we offer bundled services, so ask us what’s included.
Eric & Janelle Boyenga
Realtors DRE01254724 / 01254725
Realtors DRE01254724 / 01254725