Start with a professional appraisal or comparative market analysis
The most reliable way to know your home's value is to get a professional appraisal from a licensed appraiser in your state. An appraiser physically inspects your property, measures the structure, checks the condition of systems like plumbing and electrical, and compares it to similar homes that sold recently in your area. This takes two to four weeks and costs between $300 and $500 depending on your home's size and location.
If you need a faster, lower-cost starting point, a comparative market analysis (CMA) from a real estate agent is free or low-cost. An agent pulls recent sales of similar homes near you—same square footage, age, condition, and neighborhood—and shows you what they sold for. This is not an official appraisal and lenders will not accept it, but it gives you a working number in a day or two.
Key Takeaways
- A professional appraisal from a licensed appraiser is the standard that lenders and courts recognize, though it costs $300 to $500 and takes two to four weeks.
- A comparative market analysis from a real estate agent is free or cheap and takes days, but is not legally binding and lenders will not use it.
- Online home value tools like Zillow or Redfin give you a rough number in seconds but can be off by 5 to 20 percent because they use incomplete data.
- Your county assessor's value is set for tax purposes and is often lower than market value, so do not use it alone to price a sale or refinance.
- The reason you need the value—selling, refinancing, insurance, or property tax appeal—determines which method is appropriate and legally acceptable.
Understand what online home value estimates actually tell you
Websites like Zillow, Redfin, and Trulia show a Zestimate or similar automated value in seconds. These tools use public records, recent sales, and property characteristics to calculate a number. They are fast and free, but they work from incomplete information: they do not see inside your home, they do not know about recent renovations you did not permit, and they do not account for neighborhood details like a nearby highway or a school closing.
Online estimates can be off by 5 to 20 percent or more, especially in rural areas or neighborhoods where few homes sell. Use them as a starting point to understand the ballpark, not as a number to rely on for a major financial decision. If you are refinancing or selling, you will need something more solid.
Check your county assessor's value, but know its limits
Your county assessor sets a value on your home every one to three years for property tax purposes. You can find this number by searching your county assessor's website with your address or parcel number. The assessor's value is public record and free to look up.
However, the assessor's value is not the same as market value. Assessors use a formula to estimate value for tax revenue, and they often lag behind actual market prices. In many places, assessed value is deliberately kept lower than what homes actually sell for. If you are selling your home or refinancing, do not use the assessor's number alone—it will almost always understate what your home is worth. Use it as one data point, not the final answer.
Know which method to use based on why you need the value
The reason you are looking up your home's value matters, because different situations require different standards of proof.
If you are selling: Get a CMA from a real estate agent first to price your listing. If the sale moves forward, the buyer's lender will order an appraisal, and that appraisal is what determines the loan amount. You do not pay for it—the buyer does—but you should know it is coming.
If you are refinancing: Your lender will order and pay for an appraisal. You cannot use an online estimate or the assessor's value. The appraisal determines how much you can borrow against your home's equity.
If you are appealing your property taxes: You can use an appraisal, recent comparable sales, or a CMA to argue that your assessed value is too high. Each county has a deadline and a process—usually a form you file with the assessor's office or an appeal to the county board of review. Check your county assessor's website for the deadline and required documents.
If you are updating your homeowners insurance: Call your insurance company and ask what they use to set your coverage limit. Some use the assessed value, some use an online tool, and some use their own estimate. If your home has been significantly improved or if the value has risen, you may be underinsured. An appraisal gives you a solid number to show your insurer.
Use recent comparable sales in your neighborhood as a reality check
Pull up your county's property records or a site like Zillow and search for homes that sold in the last three to six months within a half-mile of yours. Look for homes with similar square footage, lot size, age, and condition. Note what they sold for and when.
If your home is newer or in better condition than the comparables, add 5 to 10 percent. If it needs work, subtract. If it is in a more desirable part of the neighborhood, add. This is not scientific, but it grounds you in what actual buyers have paid recently. If an online estimate or an agent's CMA seems way off from what you see in the comps, ask why.
Get an appraisal when the stakes are high
If you are making a decision that costs you thousands of dollars—refinancing, selling, or contesting your property tax assessment—pay for a professional appraisal. The $300 to $500 cost is small compared to the money at stake. An appraisal is a legal document that holds up in court, in a refinance, and in a tax appeal. Online tools and assessor values do not.
To find a licensed appraiser, ask your lender for a referral, search your state's appraisal board website, or ask a real estate agent. Make sure the appraiser is licensed in your state and has experience with homes like yours. Ask upfront what the fee is and how long it will take.
Understand how recent renovations and major repairs affect value
A new roof, updated kitchen, or finished basement can raise your home's value, but not dollar-for-dollar with what you spent. A kitchen remodel that cost $20,000 might add $12,000 to $15,000 to your home's value. A new roof adds roughly what it cost. A finished basement adds less than half of what you spent, because buyers value it less than a professionally built space.
Appraisers and agents see the receipts and permits you have, so they know what work was done and when. If you did major work without a permit, tell the appraiser anyway—they may find out during inspection, and transparency is better than surprise. Unpermitted work can lower value because it raises questions about whether the work was done to code.
Frequently Asked Questions
Can I use an online home value tool to refinance my mortgage?
No. Lenders require a professional appraisal ordered through their process. An online estimate is not legally binding and does not meet lending standards. Your lender will order the appraisal and charge you the fee, usually $300 to $500.
What if the appraisal comes in lower than I expected?
You can ask the appraiser to reconsider if you believe there is an error—for example, if they missed a recent renovation or used the wrong comparable sales. Some appraisers will review their work. If you disagree with a lender's appraisal, you can order a second one at your own cost, though lenders are not required to use it.
How often does my home's value change?
Home values shift with the market, which varies by region and year. Your assessed value updates every one to three years depending on your county. If you need a current value for a major decision, get a fresh appraisal or CMA rather than relying on one from two years ago.
Is my home worth more than the assessor says?
Usually yes. Assessed values are set for tax purposes and are often lower than market value. If you believe your assessed value is too high relative to recent sales in your area, you can file an appeal with your county assessor's office. The deadline and process vary by county.
Do I need an appraisal to sell my home?
You do not need one to list your home, but the buyer's lender will order one before they close the loan. You should get a CMA from a real estate agent to price your listing correctly. If the appraisal comes in low, it can delay or kill the sale.