The three main ways to find your house's value
Your house's value depends on who is asking and why. A tax assessor, a mortgage lender, and a buyer will each arrive at a different number. For a rough estimate you can do yourself, use online home value tools like Zillow, Redfin, or your county assessor's website. For something closer to what you could actually sell it for, you need either a professional appraisal or a comparative market analysis from a real estate agent. For tax purposes, you use your county's assessed value.
The difference between these numbers matters. Your county assessment is usually lower than market value and is what your property taxes are based on. An appraisal is what a lender uses to decide how much they will loan you. A market analysis is what an agent uses to price your home for sale. None of these is "the" value of your house — they are all correct for their specific purpose.
Key Takeaways
- Online tools like Zillow and your county assessor's website give you a free starting point, but they use incomplete data and are often off by 5 to 20 percent.
- A professional appraisal costs $300 to $500 and is required by lenders; it is the most accurate for mortgage purposes but not for selling.
- A comparative market analysis from a real estate agent is free and shows what similar homes in your area actually sold for, making it the best guide for listing price.
- Your county's assessed value is lower than market value and is used only for property tax calculations, not for selling or refinancing.
- The time of year, local market conditions, and recent sales of similar homes all shift your house's value, so estimates from six months ago may no longer be accurate.
Using online tools to get a quick estimate
Websites like Zillow, Redfin, Trulia, and Realtor.com pull data from public records, recent sales, and tax assessments to generate an estimate called a "Zestimate" (Zillow) or "Redfin Estimate." You enter your address and get a number in seconds. These tools are free and useful for a rough sense of direction, but they are not precise. They work best in hot markets with many recent sales and worst in rural areas or neighborhoods where homes rarely change hands.
The margin of error on these estimates is typically 5 to 20 percent, meaning a $300,000 estimate could be off by $15,000 to $60,000. The algorithm does not know if your roof is new, if you have added a deck, or if your kitchen is outdated. It also lags behind the market — if your neighborhood is heating up, the estimate may be weeks or months behind. Use these tools to get a ballpark figure, not to make a financial decision.
Your county assessor's website also offers a free estimate based on the assessed value used for property taxes. Search "[your county] assessor" and look for the property search tool. The assessed value is usually lower than market value because assessments are not updated every year in most states. It is useful for understanding your tax base, but not for knowing what your house would sell for.
Getting a professional appraisal
An appraisal is a formal written estimate by a licensed appraiser who visits your home, measures it, photographs it, and compares it to recent sales of similar homes in your area. Appraisals cost $300 to $500 depending on your home's size and location. They are required by lenders before they will approve a mortgage or refinance, and they are the standard used in those transactions.
You do not order an appraisal yourself when buying or refinancing — the lender orders it and pays for it (though the cost is passed to you at closing). If you want an appraisal for your own information, you can contact a licensed appraiser directly through your state's appraisal board or through a local real estate office. The appraiser will need access to your home's interior, so plan for a one- to two-hour visit.
An appraisal is more accurate than an online estimate because it is based on an actual inspection and recent comparable sales. However, it is designed for lending purposes, not for selling. If you are listing your home, a real estate agent's market analysis is more useful because it reflects what buyers in your market are actually paying right now.
Using a comparative market analysis to price for sale
If you are thinking about selling, a real estate agent will prepare a comparative market analysis (CMA) at no cost. The CMA shows what homes similar to yours — same size, age, condition, and location — sold for in the past three to six months. It also shows homes currently listed and homes that did not sell. This is the most practical guide to what your house is worth in the current market.
To get a CMA, contact two or three agents in your area and ask them to prepare a market analysis. They will visit your home, take notes on its condition, and pull recent sales data from the local multiple listing service (MLS). The analysis usually takes a few days. Different agents may arrive at different prices depending on which comparable sales they weight most heavily, so seeing multiple analyses gives you a range.
A CMA is free because the agent is hoping you will list with them. It is not a binding appraisal — it is an opinion based on market data. But it is grounded in actual recent sales in your neighborhood, which makes it far more useful than an online estimate if you are seriously considering selling.
Understanding your county's assessed value
Every property has an assessed value set by your county or local tax assessor. This value is used to calculate your property tax bill. In most states, assessed value is lower than market value — sometimes significantly lower. The ratio varies by state and county; some reassess every year, others every three to five years, and a few only when the property changes hands.
You can find your assessed value by searching your county assessor's website (search "[your county] assessor property search") or by calling the assessor's office. The assessed value is public record. If you believe the assessment is wrong — for example, if it lists your home as having four bedrooms when it has three — you can file a formal challenge called an assessment appeal or grievance. The process and deadline vary by state, so check your county assessor's website for instructions.
Your assessed value is not what your house is worth on the open market. It is a number used only for tax purposes. Do not confuse it with market value when you are thinking about selling or refinancing.
What affects your house's value right now
Your home's value shifts with the local market, interest rates, and the season. In a buyer's market (more homes for sale than buyers), values tend to soften. In a seller's market (more buyers than homes), values rise. Interest rates also matter — when rates are high, fewer people can afford to borrow, which can push prices down. Spring and summer typically see more sales activity and higher prices than fall and winter.
Recent renovations, a new roof, updated systems, and good condition all increase value. Deferred maintenance, outdated kitchens and bathrooms, and structural issues decrease it. The size of your lot, proximity to schools and transit, and neighborhood trends also play a role. An online estimate from six months ago may no longer reflect these changes or shifts in your local market.
If you need to know your home's current value for a specific reason — refinancing, selling, estate planning, or insurance — get a fresh estimate. Do not rely on a number from months ago.
Frequently Asked Questions
How often should I check my home's value?
If you are not planning to sell or refinance, checking once a year is enough. If your market is moving fast or you are actively considering a sale or refinance, check every three to six months. Online estimates update frequently, but they lag behind actual sales by weeks or months, so a fresh check is more useful than a stale one.
Why is my Zillow estimate so different from what an agent told me?
Online tools use incomplete data and do not account for your home's specific condition, recent upgrades, or neighborhood-level details. An agent's analysis is based on actual recent sales of comparable homes and a physical inspection. The agent's number is usually more accurate for your local market, especially if you are selling.
Do I need an appraisal if I am just curious about my home's value?
No. Start with a free online estimate or your county assessor's value. If you need a more precise number for selling or refinancing, ask a real estate agent for a market analysis (free) or order an appraisal ($300 to $500). An appraisal is only required by lenders, not for your own information.
Can I use my assessed value as my home's market value?
No. Assessed value is used only for property taxes and is usually much lower than what your home would sell for. For market value, use an online estimate, a real estate agent's analysis, or a professional appraisal.
What if I disagree with my county's assessed value?
You can file an assessment appeal or grievance with your county assessor. The deadline and process vary by state, so check your county assessor's website for instructions. You will need to show evidence that the assessment is wrong — for example, incorrect square footage or a missing room.