Oct 28, 2026 · By Oanh Nguyen · Broker & Loan Officer · Selling
It is the first question almost every homeowner asks me. Sometimes it comes up because they are ready to sell. Sometimes they are just curious. Either way, it is a smart question to ask.
The short answer: your home is worth what a ready, able buyer will pay for it, in today's market, in its current condition. No website, mailer or headline can tell you that exact number. But you can get very close with the right method.
In this post, I will explain how home values are estimated, why online numbers often disagree, what moves the value of a Bay Area home and how to prepare for a pricing review. All market data runs through September 2026, and every number has a source.
Why Online Estimates Vary So Much
Most homeowners start with an online estimate. That is fine as a first look. Just know what you are looking at.
Online estimates come from computer models. The models use public records, past sales and listing data. They do not walk through your home. They do not see your new kitchen, your cracked foundation or your view.
Redfin publishes the accuracy of its own estimate. As of October 29, 2026, Redfin reports a median error of 1.99% for homes for sale in California. For homes not for sale, the median error is 6.68%. Only 39.80% of off-market California estimates land within 5% of the final sale price.
That last number matters. Most homeowners asking "What is my home worth?" are not on the market yet. So their estimate falls into the less accurate group.
Here is what a 6.68% median error can mean in dollars. This is a simple, hypothetical calculation, not a real home. On a $1,500,000 home, 6.68% is about $100,200. And a median error means half of estimates miss by more than that.
Online estimates for homes that are for sale are more accurate for a simple reason. The model can see the list price. Once your home is on the market, the estimate often moves toward your asking price.
So use online estimates as a starting point. Don't set a price with them.
What Actually Sets Value: Three Methods
There are three common ways to estimate what a home is worth. Each one has a purpose.
1. Comparative Market Analysis (CMA)
A CMA is what I prepare for sellers. It compares your home with recent sales nearby that are similar in size, age, style and condition. It also looks at homes that are for sale now, pending sales and listings that did not sell.
A CMA is not an appraisal. It is a market-based opinion of price, built to help you decide how to list.
2. Appraisal
An appraisal is done by a licensed appraiser. Most buyers who get a loan will need one, because the lender wants to know the home supports the loan amount.
The appraiser also uses comparable sales. But they follow strict rules and look backward at closed sales. They usually cannot give full weight to what buyers are doing this week.
If you want an independent value before you list, such as for an estate, a divorce or a family buyout, you can hire an appraiser yourself. For legal or tax uses, ask your attorney or CPA what kind of valuation you need.
3. Automated Valuation Model (AVM)
An AVM is the computer model behind online estimates. It is fast and free. As shown above, it can also miss by a lot when the home is not on the market.
Quick Comparison
| CMA | Appraisal | Online estimate (AVM) | |
|---|---|---|---|
| Who prepares it | Real estate agent | Licensed appraiser | Computer model |
| Sees inside your home | Yes | Yes, in most cases | No |
| Uses current listings | Yes | Limited | Sometimes |
| Main purpose | Set a list price | Support a loan or legal need | Quick first look |
| Cost to you | Usually free from an agent | Paid | Free |
The Bay Area Market Right Now
Value always sits inside a market. Here is what the public data showed through September 2026.
County single-family medians (C.A.R.):
| County | Median price, Sept 2026 | Change vs. Sept 2025 | Unsold Inventory Index |
|---|---|---|---|
| Santa Clara County | $1,920,000 | -4.0% | 2.1 months |
| Alameda County | $1,265,000 | +1.2% | 2.2 months |
| California | $899,720 | n/a | 3.7 months |
Source: C.A.R. September 2026 sales and price report, released October 19, 2026. The Unsold Inventory Index shows how many months it would take to sell all homes for sale at the current pace. A lower number means a tighter market.
City medians, all home types (Redfin):
| City | Median sale price | Sale-to-list price |
|---|---|---|
| Pleasanton | $1,496,787 | 98.4% |
| Fremont | $1,370,347 | 101.0% |
| San Jose | $1,349,357 | 101.1% |
| Milpitas | $1,287,887 | 100.9% |
| Castro Valley | $1,137,958 | 103.7% |
| San Leandro | $849,595 | 105.0% |
| Hayward | $830,604 | 101.4% |
Source: Redfin city housing market pages, data through September 2026, accessed October 26, 2026.
Two things stand out. First, both counties had a little over two months of supply, well below the state's 3.7 months. Second, homes in six of these seven cities sold above list price on average.
But remember: a median is the middle sale in a whole city. It is not your home's value. For more detail, see my posts on median home prices and homes selling over asking.
What Moves the Value of a Bay Area Home
Two homes a few blocks apart can sell for very different prices. Here are the factors I look at most.
Property factors
- Size and layout. Living area matters, but so does how it flows. A usable floor plan often matters more than a few extra square feet.
- Bedrooms and bathrooms. Count matters, and so does where they are. A bedroom and full bath on the main floor can widen your buyer pool.
- Lot size and use. A flat, usable yard is valued differently from a steep or oddly shaped one. Space that could fit an accessory dwelling unit (ADU) may interest some buyers. Always check city rules before counting on that.
- Condition and updates. Roof, foundation, plumbing, electrical and windows come first. Kitchens and bathrooms come next.
- Permits. Unpermitted additions or garage conversions can affect value, financing and disclosures.
- Parking and garage. Garage space and driveway parking matter to many Bay Area buyers.
Micro-market factors
- Street and location. Busy roads, corner lots, backing to commercial uses or a quiet court all affect price.
- Home type. Detached homes, townhomes and condos are separate markets, even in the same ZIP code.
- HOA costs and rules. For townhomes and condos, monthly dues and building condition matter a lot.
- Current competition. How many similar homes are for sale right now, and at what prices?
Notice what is not on this list. I describe homes by their features and the data, not by who lives nearby. Fair housing rules matter, and they protect everyone.
How I Build a Pricing Review
When you ask me what your home is worth, here is what I do.
Step 1: Walk through your home. I note the condition, updates, layout and anything that needs repair. Photos do not show everything.
Step 2: Pull the recent comparable sales. I search MLS for sales nearby that match your home's type, size, age and style. I usually focus on the last three to six months, closer if possible.
Step 3: Adjust for differences. No two homes are the same. I adjust for size, condition, lot, garage, updates and location.
Step 4: Study the competition. Active and pending listings show what buyers can choose from today. Expired listings show what buyers rejected.
Step 5: Check the pace. I look at days on market and sale-to-list ratios for homes like yours. That tells me how buyers are reacting this month.
Step 6: Give you a range, not a single number. Then we talk about where in that range to list, based on your goals. I cover that in my post on how to price your home to sell.
How to Prepare for Your Pricing Review
You will get a more accurate number if you have this ready:
- A list of updates with the year done and rough cost. Roof, HVAC, water heater, windows, kitchen, bathrooms, flooring and paint.
- Permits and plans for any additions, remodels or ADUs.
- Past inspection reports if you have them, such as a pest, roof or sewer lateral report.
- HOA documents if you have an HOA, including the monthly dues.
- Known issues. Leaks, cracks, drainage problems or anything else you know about. It is better to discuss them early.
- Your goals. When do you want to move? Are you buying another home? What matters more, top price or a smooth timeline?
A Hypothetical Example
This example is made up to show the process. It is not based on any real home or client.
A homeowner checks two websites. One estimate says $1.45 million. The other says $1.32 million. They wonder which one is right.
I walk the home. It has a newer roof and a remodeled kitchen, but the bathrooms are original. I pull six recent sales of similar homes nearby. The three most similar homes, adjusted for size and condition, point to a range of about $1.38 million to $1.42 million.
Two similar homes are for sale now. One is priced at the top of that range and has been on the market for a month. That tells us buyers are watching price closely.
Now the homeowner has a range built on real sales, not two guesses. They can decide whether to list now, make small updates first or wait.
Frequently Asked Questions
How accurate are online home value estimates?
It depends on whether the home is on the market. Redfin reports a 1.99% median error for California homes for sale and 6.68% for homes not for sale, as of October 29, 2026. Half of estimates miss by more than the median.
Is a CMA the same as an appraisal?
No. A CMA is a market analysis an agent prepares to help set a list price. An appraisal is a formal opinion of value from a licensed appraiser, usually required by a buyer's lender.
How much does a home valuation cost?
A CMA from a real estate agent is usually free. An appraisal you order yourself is a paid service. Prices vary, so ask the appraiser.
Do upgrades always increase my home's value?
Not dollar for dollar. Some updates help a home sell faster or draw more buyers. Others cost more than they return. I can help you decide which ones make sense before you sell.
Why is my home worth less than my neighbor's?
Size, layout, condition, lot, updates and even the timing of the sale can all make a difference. Two homes on the same street can sell for very different prices.
Are Bay Area home values going down?
The data is mixed. C.A.R. reported Santa Clara County's single-family median down 4.0% from a year earlier and Alameda County's up 1.2% in September 2026. A median can also move because a different mix of homes sold. I don't predict prices. I show you current sales.
How often should I check my home's value?
If you are not selling, once or twice a year is plenty. If you are planning to sell, a fresh review within a few weeks of listing is best, because the market moves.
Do unpermitted rooms count?
It depends. Unpermitted space can affect value, financing and what you must disclose. Talk with me early, and with an attorney or the city if you have questions about permits.
Can you value my home without seeing it?
I can give you a rough range from public data. For a number you can rely on, I need to see the home.
Will my property taxes go up if my value goes up?
Property tax rules in California are specific. Ask the county assessor or a CPA about your situation. I don't give tax advice.
The Bottom Line
Your home is worth what a buyer will pay in today's market. Online estimates are a quick first look, but they cannot see inside your home, and their error is much higher when a home is not for sale.
The most reliable number comes from recent comparable sales, adjusted for your home's condition, and checked against what is for sale right now. That is what a good CMA does.
Through September 2026, both Santa Clara and Alameda counties had about two months of supply, and homes in most cities I serve sold above list on average. But every home is different. I never guarantee a value or a sale price. I give you the facts so you can make a clear decision.
Ready for a real number? I will walk your home, pull the recent sales and give you a personalized valuation, with no pressure to list.
Sources
- Redfin, "Redfin Estimate" accuracy page (last updated October 29, 2026, accessed October 29, 2026): https://www.redfin.com/redfin-estimate
- C.A.R., "September home sales and price report," released October 19, 2026: https://www.car.org/aboutus/mediacenter/newsreleases/2026releases/sept2026sales
- Redfin housing market pages (data through September 2026, accessed October 26, 2026): https://www.redfin.com/city/17420/CA/San-Jose/housing-market · https://www.redfin.com/city/12204/CA/Milpitas/housing-market · https://www.redfin.com/city/6671/CA/Fremont/housing-market · https://www.redfin.com/city/8439/CA/Hayward/housing-market · https://www.redfin.com/city/21841/CA/Castro-Valley/housing-market · https://www.redfin.com/city/17447/CA/San-Leandro/housing-market · https://www.redfin.com/city/14986/CA/Pleasanton/housing-market
Request a personalized home valuation. Call or text me at 408-780-1188, or email onrealtygroup@gmail.com.
Oanh Nguyen · Broker & Loan Officer · On Realty Group, brokered by LPT Realty · BRE #02133991 · NMLS 2020335
Equal Housing Opportunity.
Disclaimer: This post is general information only, not an appraisal or legal, tax or financial advice; data comes from the public sources linked above, is believed reliable but not guaranteed, and can change at any time.