You already know the number I'm talking about. You typed your address into Zillow, and a big bold Zestimate popped up telling you what your home is worth. Maybe you check it every few weeks. Maybe it jumped $20,000 last month and made your day — or dropped and ruined it.

Here's what most people never hear: that number is a guess made by a computer. And when your home isn't for sale, it's the least accurate guess Zillow ever makes about your house.

I'm not saying that to talk you out of using Zillow. I use it too. But if you're leaning on that Zestimate to decide whether to sell, refinance, or price your home, you're making a big decision on a shaky number. Let me show you exactly why, in plain English.

First, what a Zestimate actually is

A Zestimate is not an appraisal. Nobody walked through your home. Nobody saw your new kitchen, your fresh paint, or the fact that your backyard sits right on a busy street.

It's a computer program. It pulls public records — your square footage, your lot size, your tax history — and looks at what similar homes nearby sold for. Then it does the math and gives you a number. That's the whole thing.

So it's only as good as the information it has. And the information it has is almost always missing the parts that matter most.

The two very different numbers Zillow doesn't show side by side

Here's the part that surprises people. Zillow actually publishes how accurate its own Zestimates are. But there are two numbers, and they're worlds apart.

For homes that are actively listed for sale , Zillow's typical miss is small — right around 2%. That sounds great.

But for homes that are not for sale — which is almost certainly your home right now — the typical miss jumps to about 7%.

That second number is the one that matters to you. If you're just checking your Zestimate at home, you ARE an off-market home. You're looking at the 7% number, not the pretty 2% one.

Why the number you're looking at is the worse one

When your home goes up for sale, Zillow suddenly has fresh information — a real list price, real photos, real buyer activity. So the Zestimate quietly slides closer to that list price. Then the home sells, Zillow compares its estimate to the final price, and says “look how close we were!”

But that accurate number only showed up after you already did the hard work of pricing and listing. The number you see today, sitting at home with your house off the market, is the early, low-information version. It's the guess with the least to go on.

The more unique your home, the worse Zillow does

Zillow does its best work in neighborhoods full of near-identical homes that sell all the time. Plenty of recent, matching sales gives the computer a lot to compare against.

The moment your home is different, that breaks down. A custom build. Upgrades the neighbors don't have. A place on acreage with no real match nearby. When few homes like yours have sold, the computer is basically guessing, and the miss gets a lot bigger — for homes like that the error can run closer to 9 or 10%, sometimes more.

The nicer and more one-of-a-kind your home is, the more likely Zillow is wrong about it — in the direction that costs you money.

The things a computer will never see

• The $80,000 kitchen you just put in
• Your brand-new roof — or your worn-out one
• The view off your back patio
• Whether it's been updated or it's all still original
• How your home actually feels the moment you walk in

These are the exact things buyers pay more — or less — for. And every one of them is invisible to the algorithm.

So how do you find your home's real number?

You get a person who does what the computer can't.

It's called a CMA — a comparative market analysis. It's what I put together for every seller before we ever talk price. I look at the homes that truly compare to yours, I account for your upgrades and your condition, I factor in what's happening in your specific pocket of the valley right now, and I give you a real number you can stand behind.

Think of the Zestimate as a weather app guessing for the whole city. The CMA is me standing in your backyard, looking at your sky.

One is free, instant, and often wrong. The other is done by someone with 16 years in these exact markets — and it's the number you can actually make decisions on.

Reach out any time:

Lilly Ruiz

702-635-1105

lillysellsluxury@gmail.com

Lilly Ruiz is a luxury real estate agent with 16 years of experience, dual-licensed in Nevada and Utah, serving Las Vegas, Henderson, Summerlin, Centennial Hills, and Southern Utah. This article is for general information and is not financial or legal advice.