Who Decides What a House Is Worth?

A homeowner tells me their house is worth $500,000 because an online valuation tool says so.

The county assessor values it at $380,000.

The appraiser comes in at $465,000.

A buyer offers $450,000.

Who’s right?

Potentially all of them.

One of the most common misconceptions in real estate is that every house has a single, objective value waiting to be discovered. In reality, residential real estate is one of the few assets where several reasonable values can exist at the same time because different people are trying to answer different questions.

That distinction helps explain why homeowners, buyers, lenders, appraisers, assessors, and online valuation tools can all arrive at different numbers for the same property.

Why Sellers and Buyers Rarely Agree

Most homeowners do not look at their property the same way a buyer does.

They remember the kitchen renovation completed five years ago, the roof they replaced, the landscaping they improved, and the weekends spent maintaining the home. They know which features visitors compliment and which projects cost far more than expected.

Buyers see something different.

They are comparing the home to every other property available in their price range. They are evaluating location, condition, future maintenance, and whether another house might offer more value for the same money.

Neither side is necessarily wrong. They are simply viewing the property from different perspectives. Sellers often see value through the lens of investment and experience, while buyers view value through the lens of alternatives and affordability.

The Value a Lender Is Willing to Support

When a lender orders an appraisal, the goal is not to determine what the seller thinks the home is worth or even what a particular buyer is willing to pay.

The appraiser is developing a professional opinion of market value based on recent comparable sales, market conditions, and the property’s characteristics. That opinion helps the lender determine whether the property supports the amount being borrowed.

This is why a home can attract multiple offers at one price and still appraise for something different. The buyer and seller are negotiating a purchase. The appraiser is estimating market value. While those numbers often align, they are not required to.

That does not mean the appraiser is wrong, nor does it mean the buyer and seller are wrong. They may simply be answering different questions.

The Value the Government Uses

Property assessments create another layer of confusion.

Many homeowners assume their assessed value reflects what their home would sell for on the open market. In reality, assessments are developed for taxation purposes, not for buying and selling decisions.

Assessment methodologies vary by jurisdiction, update cycles differ, and values often lag behind changing market conditions. As a result, an assessed value may be significantly higher or lower than what a buyer would actually pay today.

That does not necessarily mean the assessment is inaccurate. It means the assessment was created for a different purpose.

The Value the Internet Thinks It Is

Online valuation tools have become incredibly popular because they provide instant answers.

The challenge is that real estate rarely fits neatly into an algorithm.

An online estimate may know the square footage, lot size, bedroom count, and recent sales nearby. What it often cannot fully account for are factors such as condition, quality of updates, floor plan functionality, deferred maintenance, views, or improvements that never made their way into public records.

Sometimes these estimates are remarkably close.

Sometimes they miss by a wide margin.

The important thing to remember is that they are estimates, not appraisals, inspections, or purchase contracts.

The Only Value That Ultimately Matters

For all the attention paid to assessments, appraisals, and online estimates, there is one value that ultimately determines whether a home sells: market value.

Even that phrase is frequently misunderstood.

People often say a house is worth whatever someone is willing to pay for it. That is only part of the equation. A house is worth what a willing buyer will pay and a willing seller will accept under normal market conditions.

If either side disagrees, a sale does not occur.

That is why market value constantly changes. Interest rates change. Inventory changes. Economic conditions change. Buyer preferences change. What buyers were willing to pay three years ago may not be what they are willing to pay today.

The house may be exactly the same.

The market is not.

So Who’s Right?

The answer depends on the question being asked.

A seller trying to decide whether to move, a lender evaluating collateral, a county determining taxes, and an online valuation model generating an estimate are all approaching value from different directions and for different purposes.

The challenge is not determining which number is universally correct. The challenge is understanding what each number represents.

Real estate is one of the few assets where multiple reasonable values can exist at the same time.

The confusion begins when people assume they are all trying to measure the same thing.

Karen Moeller
Karen Moeller
STLKaren.com
Karen.McNeill@STLRE.com
314.678.7866

About the Author:
Karen Moeller is a St. Louis area REALTOR® with MORE, REALTORS® and a regular contributor to St. Louis Real Estate News, helping clients make informed, data-driven decisions.

📬 Stay Ahead of the St Louis Market

Get local real estate updates, trends & insights — as soon as they publish.

Homeowners, buyers, investors & agents rely on us for what really matters in STL real estate.

We don’t spam! Read our privacy policy for more info.

📬 Want St Louis real estate updates as they drop?

Comments are closed.

St Louis Real Estate Search®         St Louis Home Values

St. Louis Real Estate News        Contact Us

Copyright © 2026 Missouri Online Real Estate, Inc. - All Rights Reserved
St Louis Real Estate News is a Trademark of Missouri Online Real Estate, Inc.

Missouri Online Real Estate, Inc. 3636 South Geyer Road - Suite 100, St Louis, MO 63127 314-414-6000 - Licensed Real Estate Broker in Missouri

The owner and authors this site are providing the information on this web site for general informational purposes only and make no representations, warranties (expressed or implied) or guarantees of any kind whatsoever, as to the accuracy or completeness of any information on this site or of any information found by following any link on this site. Furthermore, the owner and authors of this site will not be liable in any manner whatsoever for any errors or omissions in information on this site, nor for the availability of this information. Additionally the owner and authors of this site will not be liable for for any losses, injuries or damages in any way from the display or use of this information or as the result of following external links displayed on this site, or by responding to advertisements displayed, or contained, on this site In using this site, users acknowledge and agree that the information on this site does not constitute the provision of legal advice, tax advice, accounting services, investment advice, or professional consulting of any kind nor should it be construed as such. The information provided herein should not be used as a substitute for consultation with professional tax, accounting, legal, or other competent advisers. Before making any decision or taking any action on this information, you should consult a qualified professional adviser to whom you have provided all of the facts applicable to your particular situation or question. None of the tax information on this web site is intended to be used nor can it be used by any taxpayer, for the purpose of avoiding penalties that may be imposed on the taxpayer.
All of the information on this site is provided as is, with no assurance or guarantee of completeness, accuracy, or timeliness of the information, and without warranty of any kind, express or implied, including but not limited to warranties of performance, merchantability, and fitness for a particular purpose.
This site contains external links to other sites not owned or controlled by the owner of this site, therefore the owner of this site does not control or guarantee in any manner the accuracy or relevancy of any information obtained through following such links. Links contained on this site are for users convenience and users should exercise extreme caution when following links. Including a link on this site does not constitute an endorsement of the site linked to or any views or opinions expressed on the site, products or services offered on outside sites or the companies or organizations that own and operate outside sites.
This site may accept payment for advertising, for displaying advertisements, through affiliate relationships with companies or may receive referral fees or commissions from companies as a result of recommending or referring people to a website. This site may also accept free product samples, free services, gift cards or cash to review a product or service. All paid and sponsored content may not always be identified as such. Any product claim, quote or other representation about a product or service should be verified with the manufacturer or provider.