The three main ways to find your home's value
Your home's value depends on what someone would pay for it today, not what you paid for it or what you owe on the mortgage. The three most common ways to find this number are a professional appraisal, an automated estimate from a real estate website, and a comparative market analysis from a real estate agent. Each method costs different amounts, takes different time, and gives you different levels of detail.
An appraisal is an official assessment by a licensed appraiser who inspects your home in person, measures the rooms, checks the roof and foundation, and compares it to similar homes that sold recently in your area. This is the most expensive option — appraisals typically cost $300 to $500 — but it is also the most thorough and the one lenders require when you refinance or take out a home equity loan. An appraisal takes one to two weeks from the time you order it.
An automated estimate (sometimes called an automated valuation model or AVM) is a number generated by software using public records, recent sales, and property data. Websites like Zillow, Redfin, and Realtor.com all offer free estimates. These are fast and free, but they are less accurate than an appraisal because the software has never seen your home and cannot account for recent renovations, damage, or unique features. The estimate updates as new sales data comes in.
A comparative market analysis (CMA) is a report prepared by a real estate agent showing what similar homes in your neighborhood sold for recently. This is free if you are considering selling or refinancing, because agents offer it as part of their service. It falls between an appraisal and an online estimate in accuracy and detail. The agent will visit your home and ask about recent upgrades, which the automated estimate cannot do.
Key Takeaways
- A professional appraisal costs $300 to $500, takes one to two weeks, and is required by lenders for refinancing or home equity loans.
- Free online estimates from Zillow, Redfin, or Realtor.com are fast but less accurate because they cannot see your home or account for recent work you have done.
- A real estate agent will prepare a comparative market analysis for free if you are considering selling or refinancing, and it includes details about your specific home.
- Your home's value changes as the market changes and as new sales data becomes available, so estimates from different sources or different dates may not match.
When you need an appraisal versus when an estimate is enough
If you are refinancing your mortgage, taking out a home equity line of credit (HELOC), or applying for a home equity loan, your lender will order an appraisal. You do not choose the appraiser — the lender does — and you pay for it as part of the loan process. The appraisal protects the lender by confirming that the home is worth at least as much as the loan amount.
If you are selling your home, you do not need an appraisal. Instead, you and your real estate agent will use recent sales of comparable homes to set the listing price. The agent's comparative market analysis serves this purpose.
If you are simply curious about your home's value for tax planning, insurance purposes, or general knowledge, a free online estimate is usually sufficient. These estimates are updated regularly and give you a ballpark figure without cost or delay. If the estimate seems far off from what you expect, you can order a full appraisal to confirm, but most homeowners start with the free tools.
How to use online home value tools
Most online estimates require only your address. Go to Zillow.com, Redfin.com, or Realtor.com, enter your street address in the search box, and the site will display an estimated value within seconds. The estimate appears alongside information about the number of bedrooms, bathrooms, square footage, lot size, and the year the home was built — all pulled from public records.
After you see the estimate, look for a link or button that says "See full details" or "Home details." This will show you the recent sales history of your home (if you have sold it before), the tax assessment value, and a list of recent sales of similar homes nearby. This comparison is useful because it shows you which homes the algorithm used to reach its estimate.
Keep in mind that online estimates can be off by 5 to 20 percent or more, depending on how unique your home is and how recently homes sold nearby. If your home has been heavily renovated, is in a rural area with few recent sales, or has unusual features, the estimate will be less reliable. You can also claim your home on these sites and add information about recent upgrades (new roof, kitchen remodel, etc.), which may adjust the estimate upward.
What affects your home's estimated value
The primary factors are location, condition, size, and recent sales of similar homes. A home in a neighborhood where prices are rising will show a higher estimate than the same home in a neighborhood where prices are flat or falling. A home that needs a new roof or has outdated systems will be valued lower than an identical home in good condition.
Square footage matters, but so does layout. Two homes of the same size can have different values if one has an open floor plan and the other has many small rooms. Recent renovations — a new kitchen, updated bathrooms, new flooring — can raise the estimate. Conversely, deferred maintenance (a roof nearing the end of its life, old HVAC, foundation cracks) will lower it.
The number of bedrooms and bathrooms affects value, but not always in a straight line. A fourth bedroom that is very small may add less value than a larger third bedroom would. Lot size matters in some markets more than others; in dense urban areas, lot size has less impact than in suburban or rural areas.
School district quality, proximity to transit, and neighborhood amenities (parks, shopping, restaurants) also influence value, though online tools capture these factors less precisely than an in-person appraiser would.
Why estimates from different sources don't always match
Zillow, Redfin, and Realtor.com use different data sources, different algorithms, and different time windows for recent sales. One site might weight recent sales more heavily, while another includes older sales to account for slower markets. This means the same home can show three different estimates on three different websites.
The estimates also update on different schedules. When a home sells in your neighborhood, that sale data takes time to be recorded, verified, and fed into each company's system. One site may have the new sale data within days; another may take weeks. This lag can cause estimates to drift apart temporarily.
If you see a large gap between estimates — say, $50,000 or more on a $300,000 home — it usually means the algorithms disagree about which comparable sales are most relevant. This is a sign that an appraisal or a conversation with a real estate agent would be worthwhile, because the discrepancy suggests your home has features that automated tools are not capturing well.
How to prepare information for an appraisal
If you decide to order an appraisal, gather documents about recent work you have done: receipts for a new roof, HVAC system, water heater, kitchen or bathroom remodel, or any major repair. The appraiser will ask about these upgrades, and having documentation helps them understand what was done and when.
Make a list of any energy-efficient upgrades — new windows, insulation, solar panels, a heat pump — because these can add value. Also note any unique features: a finished basement, a deck or patio, a garage conversion, or a home office addition. The appraiser will see these during the inspection, but mentioning them upfront ensures they are not overlooked.
Clean and declutter before the appraisal. The appraiser is assessing the home, not your belongings, and a clean home makes it easier for them to see the condition of walls, floors, and fixtures. Make sure they can access all areas, including the attic, basement, and crawl space if one exists.
How home value estimates affect taxes, insurance, and refinancing
Your county assessor sets the assessed value of your home for property tax purposes. This is usually lower than the market value (what someone would pay for it), and it does not automatically update when your home's market value changes. You can challenge your assessment if you believe it is too high, but the process varies by county.
Your homeowners insurance company may use an estimate of your home's replacement cost (what it would cost to rebuild it from scratch) rather than its market value. This is different from what Zillow shows. If you are concerned your insurance coverage is too low, ask your agent for a replacement cost estimate.
When you refinance, the lender orders an appraisal and uses that number to determine how much you can borrow. If your home's value has risen, you may be able to borrow more through a cash-out refinance. If it has fallen, you may owe more than the home is worth (being "underwater"), which affects your refinancing options.
Frequently Asked Questions
How often do online home value estimates update?
Most sites update estimates monthly or quarterly as new sales data becomes available. Some update more frequently in hot markets. You can check the same address on the same site weeks apart and see the estimate shift slightly. Major changes usually reflect new sales of comparable homes nearby.
Can I use an online estimate to refinance my home?
No. Lenders require a professional appraisal ordered through their process. Online estimates are for your own information only. The lender will not accept a Zillow estimate as proof of value.
What if my home's online estimate seems way too high or too low?
Check the comparable sales the site lists to see if they make sense. If the algorithm included a very different home (wrong number of bedrooms, much larger or smaller lot), the estimate may be off. You can also contact a local real estate agent for a free comparative market analysis to get a second opinion.
Do I need to pay for a home appraisal if I am just curious about my home's value?
No. Free online estimates from Zillow, Redfin, or Realtor.com are sufficient for general knowledge. Pay for an appraisal only if a lender requires it or if you need an official value for a specific purpose like a home equity loan.
Does adding a room or renovating my kitchen automatically increase my home's value?
Not automatically. The value increase depends on the quality of the work, local market conditions, and whether the upgrade matches what buyers in your area expect. A kitchen remodel in a neighborhood where homes typically have updated kitchens may add value; the same remodel in a neighborhood where most homes have older kitchens may add less. An appraiser can tell you whether a specific upgrade is likely to pay back its cost.