Why Is Your Zestimate Off on a $1M+ Chandler or Tempe Home?
Your Zestimate is often off on a $1M+ Chandler or Tempe home because there are few truly similar sales to compare it to, and the algorithm can't see what makes your home different, like how usable the lot is, flood irrigation, lake frontage, or a recent remodel. Zillow's own numbers show a median error of 5.13% for off-market homes in the Phoenix area, which is about $61,000 on a $1.2 million home. A pricing analysis built on recent closed sales and the current competition will get you much closer.
How accurate is the Zestimate in the Phoenix area?
Zillow publishes its own accuracy numbers, which is honest of them. Here's what they show for the Phoenix metro as of October 2026.
For homes listed for sale, the median error is 1.26%. For homes that aren't for sale, it's 5.13%. Nationwide, those numbers are 1.83% and 7.01%.
If you're not selling yet, the 5.13% is the one that applies to you. And "median" is doing a lot of work in that sentence. It means half of off-market homes miss by less than 5.13%, and half miss by more.
On a $1.2 million home, 5.13% is about $61,000. That's a very nice truck. And again, half of homes miss by more than that.
The on-market number is tighter for a simple reason. Once a home is listed, there's an asking price and fresh listing details for the model to work with. That's not much help when you're trying to figure out what to list for in the first place.
Why does Zillow struggle with $1M+ homes in Chandler and Tempe?
An algorithm prices a home by comparing it to other homes. That works well in a neighborhood full of similar houses from the same builder, built in the same few years. It works less well when there aren't many good matches.
At $1M+ in South Chandler and South Tempe, there just aren't many sales to compare. Fewer homes sell at this price than at lower prices, so each estimate leans on a small, sometimes stale handful of examples.
South Tempe makes this even harder. Many of the high-end homes there are older custom builds, and no two are alike. One street might have an older ranch home on an acre, then a rebuilt modern home, then a horse property. I get into why in why South Tempe homes look so different from each other.
An algorithm sees "similar size, similar street" and blends them together. A buyer sees three completely different houses at three completely different prices.
What can't the Zestimate see about your home?
Public records cover the basics, like square footage, bedrooms, bathrooms, lot size, and year built. They miss most of what decides price at this level.
How usable the lot is. Records show the lot size. They don't show whether it's a flat, open acre or a long, narrow strip. Buyers looking at the big lots in South Chandler know the difference right away.
Flood irrigation. Some South Tempe and Chandler properties have it. Some buyers love it. Some don't want the upkeep. The algorithm doesn't know it's there either way.
Lake frontage. A home on the water in Ocotillo and one a block back can look alike on paper. Buyers shopping waterfront luxury homes don't price them alike.
Renovations. A full remodel only shows up if a permit or an old listing recorded it. Otherwise, Zillow still thinks you have the original kitchen.
What's around you. Backing to a freeway versus open space. A quiet cul-de-sac versus a busy street. A view versus a block wall.
Each of these can swing value a lot, in either direction. A Zestimate can be too high as easily as too low. Too high is the more dangerous one, because it's the one people want to believe.
Is the Zestimate ever useful?
Sure. It's a fine way to watch the general direction of your area over time. If it's been sliding for a year, that's worth noticing.
Just don't price from it, and don't use it to argue with an offer. Buyers and their agents know it's an estimate. Appraisers work from closed sales, not website estimates.
Think of it like a bathroom scale at the gym. Good for spotting a trend. Not what the doctor writes in your chart.
What should you use instead of a Zestimate?
A real pricing analysis. It's the same basic work an appraiser does, done by someone who has actually walked through your home.
It starts with recent closed sales of homes that are truly similar: same area, similar lot, similar condition, similar features. Then it adjusts for the differences. Your remodeled kitchen counts. So does the freeway noise behind the house down the street.
Then it looks at the competition. What's for sale right now, at what price, and how long has it been sitting? Buyers compare your home to the ones they can tour this weekend, not to a sale from two years ago.
Put those together and you get a number you can defend to a buyer, and to an appraiser if the buyer is financing. It also tells you which side of a price line your home sits on, which matters more than you'd think. More on that in whether to list at $999,000 or $1 million.
If you want to see how pricing fits into the whole sale, start with how your home gets sold.
Quick answers
How accurate is the Zestimate in Phoenix?
According to Zillow, the median error in the Phoenix metro is 1.26% for homes listed for sale and 5.13% for homes that aren't. Half of homes miss by more than those numbers.
Why is my Zestimate higher than my home is worth?
The algorithm may be comparing your home to sales that aren't truly similar, or missing something like a busy street behind you or an older interior. A pricing analysis based on recent closed sales will show where the gap comes from.
Do appraisers use the Zestimate?
No. Appraisers base value on recent closed sales of similar homes and adjust for the differences between them.
If you'd like a real number for your home instead of a website's best guess, I'll put one together for you. Call or text me at 480-448-2020, or book a time to talk.
