Last updated October 21, 2026
The Zestimate is the most-checked number in St. Louis real estate and one of the most misunderstood. Here’s what Zillow’s own accuracy data shows for St. Louis, why it misses here, and what to use before you price a house or write an offer.
Less than most people think for a house that isn’t for sale. Zillow’s own table puts the St. Louis median error for off-market homes at 7.88%, with 34.70% of Zestimates within 5% of the eventual sale price and 58.93% within 10%. Zillow’s St. Louis numbers ↓
On a $300,000 St. Louis house, the 7.88% median error means half of Zestimates miss the sale price by more than about $24,000, too high or too low. About one in five misses by more than 20%, or $60,000. Zillow doesn’t publish which way the St. Louis misses lean, but in my experience, Zillow and Realist values on St. Louis homes more often miss low. What the misses look like ↓
Because it can see the list price. For St. Louis homes on the market, Zillow reports a 1.79% median error, with 85.41% within 5% of the sale price, against 7.88% for homes that aren’t listed. Once a house is listed, the Zestimate partly echoes the asking price, so it can’t tell you whether that price is right. On-market vs. off-market ↓
No. Price it from the comparable sales that actually competed for the same buyers, adjusted for the season and the condition of your house. A list price that’s off by 8% either leaves money on the table or misses the first weekend, when most offers come. How I find the right list price →
No. Comps first, concessions second, and days on market sets your leverage. A Zestimate above the asking price isn’t proof the house is a deal, and one below it isn’t proof it’s overpriced. How much to offer →
Sources: Zillow’s published Zestimate accuracy table (St. Louis metro, on-market and off-market homes), checked October 2026; 2026 St. Louis County MLS sales. Zillow updates its figures regularly.
That a Zestimate on a house that isn’t for sale is a rough starting point, not a price. These are Zillow’s published figures for the St. Louis metro, which covers about 1.1 million homes with Zestimates. Zillow doesn’t break the figures out by county, so the same numbers cover St. Louis County, the city and Jefferson County:
| St. Louis Zestimates (off-market) | Share of homes | On a $300,000 house |
|---|---|---|
| Within 5% of the sale price | 34.70% | within $15,000 |
| Within 10% | 58.93% | within $30,000 |
| Within 20% | 80.60% | within $60,000 |
| Off by more than 20% | 19.40% | more than $60,000 |
Read it the other way around: about two out of three St. Louis Zestimates miss the eventual sale price by more than 5%, and about one in five misses by more than 20%. You can’t tell from the number itself which group your house is in.
No. Once a house is listed, the model has the list price and the listing details to work with, so it tends to move toward the asking price. For about 12,600 St. Louis homes on the market, Zillow reports a 1.79% median error, with 85.41% within 5% of the sale price, 94.05% within 10% and 98.92% within 20%. Off the market, the median error is 7.88%. It’s useful for seeing what the market thinks of a listing, but it isn’t an independent check on whether the price is right.
Because the things that move St. Louis prices most are the things a model can’t see from public records.
In 2,872 St. Louis County sales in 2026, the median home was built in 1963, 43.1% were built before 1960 and 74.8% before 1980. Two houses on the same street with the same square footage can be a full renovation and an original-condition estate sale. The Zestimate sees square footage, bedrooms and nearby sales; it doesn’t see the kitchen, the roof, the sewer lateral or the basement. Home age by school district →
The items that change a home’s value that Zillow can’t see. Walkthrough Checklist: What to Look For When Buying in St. Louis → →A model treats nearby sales as evidence. A good pricing decision asks whether those sales competed for the same buyer. On a Lindbergh split-level I sold, a nearby $500,000 sale was a 1.5-story, a different kind of house with a different buyer pool, so I didn’t use it. How that pricing decision played out →
Spring comps aren’t summer or winter comps. Buyer demand rises and falls inside each year, so a value built from last spring’s sales can be too high for a house listed in November. Selling in fall or winter →
The Zestimate leans on recent nearby sales. Where few homes sell, or where the houses vary a lot, it has less to work with.
Zillow doesn’t publish a separate figure for Jefferson County; its table covers the whole St. Louis metro, which includes it. In my experience, public information on Jefferson County homes is more limited. Many tax records reflect only the first floor, so a two-story house can show far less square footage than it has. That inflates price per square foot on paper and gives an automated estimate the wrong size to start from. Before you lean on any online number there, check the square footage against the listing or the house itself. Jefferson County, MO →
Either money or time. Price 8% too high and the house misses the first weekend, when most multiple offers come, and you end up reducing anyway. Price 8% too low and you may still get multiple offers, but you started the bidding below where the market would have gone. When to lower the price →
It can push you the wrong way in either direction. A Zestimate $20,000 above the asking price can talk you into paying over when the comps don’t support it, and one below the asking price can talk you out of a well-priced house that will have offers by Sunday. Comps first, concessions second; days on market sets your leverage, not the opening number. How much to offer on a house in St. Louis →
How to build a defensible offer number from what you actually find in the home. How Repair Costs Should Affect Your Offer Price in St. Louis → →A pricing analysis built on true comparable sales: the same kind of house, sold recently, in the same season, adjusted for condition and for what else buyers can buy at that price right now. That’s what I walk sellers through before we list, and it’s what I use with buyers before we write an offer.
How the Zestimate works
No. The Zestimate is Zillow’s own model. Your assessed value comes from the county assessor, and in Missouri, residential property is assessed at 19% of its appraised market value for tax purposes. Neither is what a buyer will pay.
No. An appraisal is done by a licensed appraiser who inspects the house and picks comparable sales, usually for a lender. A Zestimate is an automated estimate from public records and listing data, with no one walking through the house.
You can update your home’s facts on Zillow, such as bedrooms, bathrooms and upgrades, and that can move the estimate. It doesn’t change what buyers will pay, which comes down to the house, the comps and the market the week you list.
Selling
Yes, and I use it strategically. If the Zestimate is significantly lower than where we’re pricing the house, I pull it before we list, so buyers aren’t anchored to a number the comps don’t support. If it’s higher, I leave it up. What a Zestimate costs a seller ↑
Zillow
That “contact agent” buttons usually go to agents who pay Zillow for your lead, not necessarily the listing agent. What happens when you click on Zillow →
This is one piece of the St. Louis home buying process. See how it all fits together:
📚 Complete St. Louis Buyer Guide →
Grew up in South St. Louis, lived in Dogtown for 6 years, now in South County. You'll find us at Wellspring on Lindbergh on Sundays. I'm not selling you a house — I'm showing you how to think about buying or selling a house.
Questions about what you are reading? I answer personally — no team, no handoff.