Assessed vs Market Value: Key Differences Every Homeowner Should Know

Yes. You can find an assessed value vs market value calculator online to estimate your taxes. You simply input your home’s estimated market value and your local assessment ratio to see what your taxable base should be.

Yes. Adding a deck or finishing a basement will increase your market value (the price a buyer will pay) and your assessed value (once the city discovers the improvement through building permits).

Not necessarily. While a rising tax value vs market value often leads to higher taxes, your bill also depends on the “millage rate” (the tax rate set by the city). If the city lowers the tax rate while property values rise, your bill might stay the same.

If you believe your assessment is too high, you can file a “tax grievance” with your local assessor’s office. You’ll need to provide evidence, such as recent comps or a professional appraisal, showing that the market value of your home is lower than the government’s estimate.

A local assessor looks at “mass appraisal” data, including your property’s square footage, the number of bedrooms, and recent sales in your specific neighborhood. They don’t usually walk through your home; they use public records and exterior inspections.

As a homeowner, you generally want a lower property tax assessment vs market value. A lower assessed value means a smaller tax bill. However, if you are trying to sell your home, a higher market value is the goal, as it represents your actual equity and profit.

Yes. If your assessed value vs market value shows that the government thinks your home is worth more than you could actually sell it for, you are being overtaxed. This is a prime time to file an appeal.

An appraisal is a detailed, professional evaluation requested by a lender to confirm the home is worth the loan amount. While an appraisal aims to find the “market value,” the “assessed value” is strictly a government calculation for taxes.

Banks care about market value because they need to know they can recoup their money if you default. The government cares about the property tax assessment because they need a standardized, predictable way to fund the local budget regardless of monthly market swings.

This happens for three main reasons: First, Assessment Ratios mean many municipalities only assess homes at a fraction of their worth (e.g., 60% or 80%). Second, Time Lags mean tax assessments are often done every 1–5 years, so they don’t reflect recent “spikes” in the market. Third, Caps mean some states have laws that limit how much an assessed value can rise each year, even if the market value skyrockets.