The three ways to find your home's value
You can find your home's value through a property tax assessment, an online estimate, or a professional appraisal. Each gives you a different number because they measure different things and use different methods. A tax assessment is what your county uses to calculate property taxes. An online estimate is a computer guess based on recent sales nearby. A professional appraisal is what a bank requires before lending you money, and it costs money but is the most thorough.
The number you get depends on which method you choose and when you check. A home's value changes as the market shifts, as nearby homes sell, and as your own home changes. You do not need all three — most people start with one and move to another only if they need a specific answer for a specific reason.
Key Takeaways
- Your county assessor's office publishes property tax assessments for free online, usually searchable by address, and these are public record.
- Online estimate tools like Zillow, Redfin, and your county assessor's own website give you a quick number but are less accurate than appraisals.
- A professional appraisal ordered through a bank or appraiser costs $300 to $500 and is required if you are refinancing or taking out a home equity loan.
- The value you see online or on a tax bill is not the same as what a buyer would pay or what a lender would lend against.
Checking your county assessor's property tax assessment
Your county assessor maintains a public record of every property's assessed value, and you can look it up for free online. Go to your county's website and search for "property assessor" or "property records." Most counties have a searchable database where you type in your address and see the assessed value, the lot size, the year built, and sometimes recent sales of comparable homes nearby.
The assessed value is not the same as market value. Assessors estimate value to calculate property taxes, and many states cap how much the assessed value can rise each year even if the market value jumps. In California, for example, assessed values are frozen at the purchase price and rise only 2 percent per year. In other states, assessments are updated every few years. The assessed value is a floor, not a ceiling — your home is usually worth more than the assessment shows.
To find your assessor's database, search "[your county name] property assessor" or "[your county name] property records." If the county website is hard to navigate, call the assessor's office directly — they can tell you the assessed value over the phone and explain how often they update it.
Using online home value estimates
Websites like Zillow, Redfin, Realtor.com, and Trulia publish estimated home values based on recent sales, property characteristics, and market trends. These estimates are free and instant. You type your address and get a number within seconds. The estimate usually comes with a range — for example, $450,000 to $475,000 — to show the uncertainty.
These estimates are educated guesses, not appraisals. They work better in hot markets with many recent sales and worse in rural areas or neighborhoods where homes rarely sell. The estimate can be off by 5 percent or 20 percent depending on how much recent data the algorithm has. If your neighborhood has not had a sale in two years, the estimate is less reliable than if three homes sold on your street last month.
Use online estimates to get a rough sense of value and to track trends over time. Check the same site every few months and see whether the estimate is rising or falling. Do not use an online estimate as proof of value for a loan, insurance claim, or legal dispute — those require an appraisal or assessment from an official source.
Getting a professional appraisal
A professional appraisal is a detailed written estimate of your home's value, prepared by a licensed appraiser who inspects the property in person. Appraisers look at the condition of the structure, the roof, the systems, the lot, and recent sales of similar homes in the area. They produce a formal report that lenders accept as proof of value.
You order an appraisal through a bank, a mortgage lender, or an independent appraiser. If you are refinancing a mortgage or taking out a home equity loan, the lender will order and pay for the appraisal — you do not choose the appraiser, but you pay the cost, usually $300 to $500. If you want an appraisal for your own information, you can hire an appraiser directly and pay out of pocket.
An appraisal takes one to two weeks and produces a detailed report. It is the most accurate method because it is based on a physical inspection and recent comparable sales, not just a computer model. However, it is also the most expensive and the slowest. Use an appraisal when you need an official value for a loan, a refinance, an insurance claim, or a legal matter.
Why different sources give you different numbers
Your county assessment, an online estimate, and a professional appraisal will almost never match. The assessment is based on tax policy and may be years old. The online estimate is based on a computer model trained on past sales. The appraisal is based on a recent inspection and current market conditions. All three are trying to answer the same question — what is your home worth — but they use different data and different methods.
The differences are normal and expected. A home assessed at $400,000 might have an online estimate of $425,000 and an appraisal of $410,000. None of these is "wrong." They are three different measurements of the same thing, like measuring your height in feet, inches, and centimeters. The appraisal is usually the most accurate for lending purposes because it is the most recent and the most thorough.
When you need to know your home's value
You might want to know your home's value for several reasons. If you are thinking about selling, an appraisal or a real estate agent's opinion is more useful than an online estimate. If you are refinancing or borrowing against your home, your lender will order an appraisal. If you are disputing your property taxes, you can challenge the assessment using recent sales data or a professional appraisal. If you are updating your homeowners insurance, your insurer may ask for the replacement cost, which is different from market value.
For most people, an online estimate is enough to satisfy curiosity or to track whether the neighborhood is appreciating. For decisions that involve money — selling, borrowing, or disputing taxes — use an assessment or appraisal instead.
Frequently Asked Questions
How often does my home's value change?
Market value changes constantly as homes sell nearby and as interest rates and demand shift. Your county assessment usually updates every one to four years depending on the state. Online estimates update monthly or quarterly as new sales data comes in. For most purposes, checking your value once or twice a year is enough.
Can I use an online estimate to refinance my home?
No. Lenders require a professional appraisal, not an online estimate. The appraisal must be ordered through the lender and performed by a licensed appraiser. The lender will not accept a Zillow estimate as proof of value because it is not an official document and has no legal standing.
What is the difference between market value and assessed value?
Market value is what a buyer would pay for your home today. Assessed value is what your county estimates for tax purposes, and it is often lower and updated less frequently. Assessed value is a starting point for property taxes, not a reflection of what your home is actually worth in the market.
Do I need to pay for an appraisal if I just want to know my home's value?
No. Start with your county assessor's website or an online estimate tool — both are free. Pay for an appraisal only if you are refinancing, taking out a loan, or need an official value for a legal or insurance matter.
Why is my online estimate so different from my neighbor's?
Online estimates are based on recent sales, property size, condition, and other factors. If your home is newer, larger, or in better condition than your neighbor's, the estimate will be higher. If your home has not sold recently and your neighbor's has, the estimate may be less accurate. Differences of 5 to 10 percent are normal.