What Your St. Louis Home Is Actually Worth — And Why Zillow Is Probably Getting It Wrong
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What Is My St. Louis Home Actually Worth?
Zillow's Zestimate has a median error rate of 7–7.49% for off-market homes nationwide—enough to be off by $20,000–$35,000 or more on a typical St. Louis property. In Missouri's partial non-disclosure counties, where sale prices aren't always public record, the algorithm has even less data to work from. The most accurate way to know what your St. Louis home is worth is a Comparative Market Analysis (CMA) from a local agent with live MLS access—someone who can factor in your home's condition, your specific block, and what buyers are competing over right now.
You pull up Zillow. You see a number. Maybe it's $315,000. Maybe it's $278,000. Either way, you start building a plan around it.
That's the problem.
Zillow's Zestimate is one of the most widely used—and most misunderstood—tools in residential real estate. For most homeowners, it's the first number they see, and it becomes the anchor for every decision that follows: what to list at, how much equity they think they have, whether now is the right time to sell. But that number is often wrong in ways that matter, and in the St. Louis market specifically, there's an additional layer most people never hear about.
Here's what's actually going on.
What Zillow's Own Data Says About Its Accuracy
Zillow publishes its own error rates—to their credit, they don't hide them. Here's what those numbers look like as of 2026:
- On-market homes (actively listed): Median error rate of approximately 1.94–2.4%. That means half of Zestimates for homes that are already listed for sale are within about 2.4% of the final sale price.
- Off-market homes (not currently listed): Median error rate of 7.06–7.49% nationwide. That means half of all Zestimates for homes not on the market miss the mark by more than 7%.
On a $300,000 home, 7.49% is $22,470. On a $400,000 home, it's nearly $30,000. That's not a rounding error—that's a meaningful miscalculation that affects whether you price competitively, whether you leave money on the table, and whether your financial plans for the proceeds hold up.
There's a subtlety worth flagging here too. When a home goes on the market, Zillow's Zestimate tends to shift toward the list price—which is why the on-market accuracy looks so much better. But that improved accuracy isn't the Zestimate "getting it right." It's the algorithm adjusting to the price that a local agent already set. The number you saw six months ago when you were privately deciding whether to sell? That one didn't have that benefit.
The Missouri Twist: Why St. Louis Is Especially Complicated for Algorithms
Here's the part that almost nobody outside the real estate industry knows about.
Missouri is what's called a
partial non-disclosure state. That means actual sale prices are not always part of the public record, and what Zillow can see depends entirely on where you are.
In
St. Louis City and St. Louis County, sale prices are disclosed and part of the public record—so Zillow has better data to work from. But in many other counties across Missouri, that information is not publicly reported. Zillow's own documentation acknowledges that accuracy varies based on the availability of local data, and in counties where that data is thin or missing, the estimates can swing significantly.
Even in St. Louis City and County—where disclosure is required—the algorithm still can't access what agents see through the MLS: the real-time picture of pending sales, what homes are actually going under contract for, how many offers a property received, or whether a buyer waived contingencies to win. That competitive intelligence is only visible to agents with active MLS access, and it's exactly the data that determines what your home is worth
right now.
What Zillow Can't See (And Why It Matters for Your Home Specifically)
The Zestimate is built on publicly available data: square footage, lot size, bedroom and bathroom count, age, and recent sale prices from similar properties. It's a legitimate starting point for a ballpark. But it has no idea about:
- The kitchen you updated last year
- The roof you replaced, or the HVAC system that's original to 1988
- The fact that your block backs to a busy commercial street while the comp two streets over backs to a park
- The deferred maintenance that a buyer's inspector is going to find
- Whether buyers are currently fighting over homes in your ZIP code or sitting on their hands
These are the factors that move the number by 5, 10, sometimes 15 percent in either direction—and they're invisible to an algorithm.
Real estate appraisers won't use a Zestimate as a basis for determining value. A CMA prepared by a local agent with MLS access accounts for condition, updates, location nuances, and current buyer behavior in a way no automated tool can replicate. It's also free—one of the few things in a real estate transaction that doesn't cost you anything upfront.
For what it's worth: not every agent builds CMAs the same way. I hold the
Pricing Strategy Advisor (PSA) Certification from the National Association of Realtors—a designation specifically focused on mastering the CMA process, pricing methodologies, and helping sellers and buyers understand the difference between an automated estimate and an actual market-supported value. It's the credential that says pricing isn't something I do casually—it's something I've trained on specifically.
What the St. Louis Market Actually Looks Like Right Now
Putting Zillow aside, here's what the numbers actually show for the St. Louis area in mid-2026:
- St. Louis City: Median sale price of approximately $255,000–$261,000 over the past three months, up about 6.2% year-over-year. Homes are averaging around 21 days on market.
- St. Louis County: Median sale price of approximately $287,500–$312,000 depending on the month, up about 3.6% year-over-year. Homes are moving in around 11 days.
- Greater St. Louis metro: Median listing price of $290,000 as of June 2026, with active inventory up about 10% from a year ago—giving buyers a bit more room to breathe while still keeping conditions relatively active for sellers.
These are metro-level numbers, and they matter for context. But they don't tell you what your specific home on your specific street in Kirkwood, Florissant, Oakville, or Webster Groves is worth. That's a different question—and the answer requires actual comp analysis, not a regional average.
What Overpricing Actually Costs You
This is the part sellers feel the most, often too late.
When a home is priced above what the market will support, a few things happen in sequence. First, showings are light—buyers who search by price range don't see it, and the ones who do show up are comparing it unfavorably to accurately priced competition. Second, days on market accumulate. In a market where well-priced homes in competitive segments are going under contract in 11 to 21 days, a listing sitting at 45 or 60 days is sending a signal:
something is off.
That signal attracts low offers. It invites buyers to ask questions. And when a price reduction finally happens, it often draws a second round of low offers from buyers who've been watching and waiting.
Ironically, a home priced correctly from day one almost always nets more than one priced too high and reduced later—even if the eventual sale price looks similar on paper. The correctly priced home sells faster, with stronger terms, fewer concessions, and less stress.
This is the math I walk every seller through before we ever decide on a number.
How to Actually Find Out What Your Home Is Worth
There's no algorithmic shortcut for this. The right answer requires:
- Real closed comps from the MLS — not estimates, not listing prices, but what homes actually sold for within the last 90 days, within a reasonable distance, with similar square footage and condition
- Active competition analysis — what's on the market right now that buyers are comparing your home against
- Condition and update adjustments — an honest assessment of what your home has going for it and what a buyer is likely to negotiate on
- Current market absorption — how quickly homes at your price point are moving, and whether you're in a segment where buyers are competing or waiting
That's a CMA. And it's the only number worth building a pricing strategy around.
Frequently Asked Questions
How accurate is Zillow's Zestimate for homes in St. Louis?
For off-market homes nationwide, Zillow's median error rate is 7–7.49%, meaning half of all Zestimates miss the actual sale price by more than 7%. In the St. Louis area, this error is compounded by Missouri's partial non-disclosure status—counties outside St. Louis City and St. Louis County don't require public reporting of sale prices, so Zillow is working with incomplete data. A local CMA from an agent with MLS access is far more reliable.
What is the current median home price in St. Louis?
As of mid-2026, the median sale price in St. Louis City is approximately $255,000–$261,000, up about 6.2% year-over-year. St. Louis County is running closer to $287,500–$312,000 depending on the month and submarket. Prices vary significantly by neighborhood, so a metro-wide number won't tell you what your specific home is worth.
What's the difference between a Zestimate and a CMA?
A Zestimate is an automated estimate generated by an algorithm using publicly available data—it can't account for your home's condition, recent updates, or the nuances of your specific block. A Comparative Market Analysis (CMA) is prepared by a local agent using real MLS data: actual closed sales, active competition, and pending contracts in your immediate area. A CMA also factors in what agents and buyers are seeing in real time, including multiple-offer activity and days-on-market trends.
Does overpricing my home hurt my sale?
Yes—significantly. Homes priced too high sit on the market, accumulate days-on-market, and typically require price reductions that signal weakness to buyers. In the St. Louis area, where homes in competitive segments are going under contract in 11–21 days, an overpriced listing stands out immediately. Once a home gets stale, buyers assume something is wrong with it—and you lose the negotiating leverage you'd have had with a correct price from day one.
How do I find out what my St. Louis home is actually worth?
The most reliable way is a Comparative Market Analysis from a local agent with active MLS access in your specific market. For a free, no-obligation CMA across St. Louis City, St. Louis County, St. Charles County, and Jefferson County, contact Cheryl Carosone at Campbell House and Home:
cheryl@chhstl.com or CherylCarosone.Realtor.
The Zestimate is a useful first glance. It's not a pricing strategy. And in the St. Louis market—where conditions vary significantly by neighborhood, where Missouri's partial non-disclosure rules limit what algorithms can see, and where the difference between a correct price and an optimistic one can mean weeks on market and thousands in concessions—you need more than an algorithm to make a good decision.
I build CMAs for sellers across St. Louis City, St. Louis County, St. Charles County, and Jefferson County—neighborhoods like Kirkwood, Webster Groves, Florissant, Oakville, Fenton, and everywhere in between. If you want to know what your home is actually worth right now, let's find out together.
Reach out:
cheryl@chhstl.com | CherylCarosone.Realtor
About Cheryl Carosone Cheryl Carosone is a Realtor with Campbell House and Home, a boutique brokerage located in St. Louis, Missouri. She holds the
Pricing Strategy Advisor (PSA) Certification from the National Association of Realtors—a specialized designation in CMA methodology and pricing strategy. She serves buyers, sellers, and investors across St. Louis City, St. Louis County, St. Charles County, and Jefferson County, with a focus on data-driven pricing, hyperlocal market knowledge, and treating every client like the knowledgeable friend she'd want in her corner. Her background in education shapes how she explains real estate—clearly, honestly, and without the sales pitch.
