Start with a free online estimate, then get a professional appraisal if you need an official number
Your home's value is what someone would pay for it today in your local market. You can get a rough estimate for free using online tools like Zillow, Redfin, or your county assessor's website. These estimates are useful for understanding your home's ballpark worth, but they are not precise — they use public records and algorithms, not an actual inspection of your property.
If you need an official value for a mortgage, refinance, insurance claim, or property tax appeal, you will need a professional appraisal from a licensed appraiser. An appraiser visits your home, measures it, inspects its condition, and compares it to similar homes that sold recently in your area. This takes one to two weeks and costs between $300 and $600 depending on your home's size and location.
Key Takeaways
- Free online estimates from Zillow, Redfin, or your county assessor give you a starting point but are not precise enough for loans or legal claims.
- A professional appraisal costs $300 to $600, takes one to two weeks, and is required by lenders before they approve a mortgage or refinance.
- Your county assessor's estimate is used for property taxes and is often lower than market value, but you can appeal it if you think it is wrong.
- Comparable sales in your neighborhood — homes similar to yours that sold in the last three to six months — are the most reliable way to estimate value yourself.
Free online tools and what they actually show you
Websites like Zillow, Redfin, and Trulia pull data from public records — past sales, tax assessments, property details — and run them through algorithms to estimate current value. Zillow calls this a "Zestimate," Redfin calls it a "Redfin Estimate." These are free and take seconds to generate.
The catch is accuracy. These estimates can be off by 5 to 20 percent or more, especially in neighborhoods where homes do not sell often or where your home is unusual in some way. They do not account for recent renovations you did, damage the algorithm cannot see, or local market shifts that happened after the last sale in your area. Use them to get a sense of the range, not as a final answer.
Your county assessor's website also shows a value estimate, usually called "assessed value" or "appraised value." This is the number used to calculate your property taxes, and it is often lower than what your home would actually sell for. You can look it up free by searching "[your county] assessor" plus your address.
How a professional appraisal works and when you need one
A professional appraisal is an official document prepared by a licensed appraiser. The appraiser visits your home, measures the square footage, notes the condition of the roof, foundation, plumbing, and electrical systems, and checks for any damage or needed repairs. They then find three to five comparable homes — similar homes in your area that sold recently — and adjust the price up or down based on differences.
Lenders require an appraisal before they approve a mortgage or refinance. They do this to make sure the home is worth at least what you are borrowing. You typically pay for the appraisal upfront, though some lenders roll the cost into your loan. If you are buying a home, the lender orders the appraisal; if you are refinancing, you order it or the lender does.
You may also need an appraisal for an insurance claim, a property tax appeal, or a divorce settlement. In those cases, you hire the appraiser yourself. The process takes one to two weeks from the time the appraiser visits to when you receive the written report.
Using comparable sales to estimate value yourself
The most reliable way to estimate your home's value without paying for an appraisal is to look at comparable sales — homes similar to yours that sold recently in your neighborhood. You can find these through your county assessor's website, Zillow's "Sold" filter, or Redfin's sales history. Look for homes that sold in the last three to six months, are similar in size and age, and are in the same neighborhood or a very similar one.
Write down the sale price of each comparable home and note how it differs from yours. If a comparable sold for $350,000 and it has an extra bedroom you do not have, subtract some amount. If yours has a newer roof and theirs does not, add some amount. This is rough math, not science, but it gives you a sense of where your home sits in the market.
Real estate agents do this work professionally and can give you a free "comparative market analysis" if you ask. They have access to more detailed sales data and local knowledge. You do not have to be planning to sell to ask for one — many agents offer them as a way to start a conversation.
Why your county assessor's value is different from market value
Your county assessor estimates your home's value for property tax purposes. This number is often lower than what your home would sell for on the open market, because assessors use different methods and update values on a schedule, not in real time. Some counties reassess every year; others do it every three to five years.
If you think your assessed value is too high, you can file an appeal with your county assessor's office. The process and deadline vary by state and county, but you typically have 30 to 60 days after you receive your assessment notice. You will need to show evidence — recent sales of comparable homes, a professional appraisal, or photos of damage or needed repairs — that supports a lower value.
What affects your home's value
Location is the biggest factor. A home in a neighborhood with good schools, low crime, and access to jobs and transit will be worth more than an identical home in a less desirable area. Within a neighborhood, homes on larger lots, with more square footage, newer construction, and fewer needed repairs sell for more.
Recent renovations — a new roof, updated kitchen, or finished basement — can raise value, but not dollar-for-dollar. You might spend $20,000 on a kitchen remodel and add $15,000 to your home's value. Damage or deferred maintenance — a roof that needs replacing, foundation cracks, or outdated systems — lowers value. Market conditions matter too. In a seller's market with few homes for sale, prices rise. In a buyer's market with many homes for sale, prices fall.
The difference between appraised value and selling price
An appraisal is an estimate of what your home is worth. The actual selling price depends on negotiation. A buyer might offer less than the appraisal, especially if the appraisal is higher than comparable sales or if the buyer finds issues during inspection. You might accept less to close the sale quickly, or you might hold out for a higher price if you have other offers.
If you are refinancing and the appraisal comes in lower than you expected, you cannot force it higher. You can ask the appraiser to reconsider if you believe they made an error, but the decision is theirs. If the appraisal is significantly lower than the loan amount, the lender may not approve the refinance, or may require you to put more money down.
Frequently Asked Questions
How often should I check my home's value?
Checking once a year using free online tools is reasonable if you are curious about your home's worth. If you are planning to sell, refinance, or appeal your property taxes, check three to six months before you need the information. Market conditions change, and a recent estimate is more useful than one from a year ago.
Can I use a Zillow estimate to refinance my home?
No. Lenders require a professional appraisal from a licensed appraiser, not an online estimate. Online estimates are too unreliable for a loan decision. Your lender will order the appraisal as part of the refinance process.
What if the appraisal is lower than I expected?
You can ask the appraiser to reconsider if you believe they made a factual error — for example, if they underestimated your home's square footage or missed a recent renovation. You can also provide additional comparable sales data. But the appraiser has the final say. If the appraisal is too low for your refinance, you may need to wait for the market to improve or explore other options with your lender.
Do I need an appraisal to sell my home?
No. A buyer's lender will order an appraisal as part of their mortgage process. You do not need one to list or sell your home. However, a professional appraisal can help you set a realistic asking price and support your negotiating position if a buyer's appraisal comes in low.
How do I appeal my property tax assessment?
Contact your county assessor's office and ask for the appeal process and deadline — usually 30 to 60 days after you receive your assessment notice. You will need to submit evidence that your assessed value is too high, such as recent comparable sales, a professional appraisal, or documentation of damage or needed repairs. Some counties allow you to appeal online; others require a written letter or in-person meeting.