Where to find property value estimates

You can find estimates of your property's value through three main routes: online assessment tools, your local assessor's office, and real estate professionals. Each gives you a different type of number, and they often disagree with each other — that is normal.

Online tools like Zillow, Redfin, Trulia, and Realtor.com pull from public records and recent sales to generate an estimate called a "Zestimate" (Zillow) or "Redfin Estimate". These are free and instant, but they are built from algorithms, not from anyone walking through your house. They tend to be less accurate for unusual properties, newly renovated homes, or houses in areas where sales are infrequent.

Your county assessor's office maintains a record of your property's assessed value for tax purposes. This is public information. You can find it by searching your county assessor's website (usually under the county government domain) with your address or parcel number. The assessed value is often lower than market value because it is used to calculate property taxes, not to reflect what your home would sell for today.

A real estate agent or professional appraiser will give you the most detailed estimate. An agent provides a Comparative Market Analysis (CMA) for free as part of their job; an appraiser charges a fee (typically $300 to $500) but produces a formal appraisal document that lenders and courts accept. Appraisers are licensed and regulated; agents are not required to be.

Key Takeaways

  • Online tools like Zillow and Redfin are free and instant but are estimates based on algorithms, not inspections of your specific house.
  • Your county assessor's office record is public and free to access but shows assessed value for taxes, which is usually lower than what your home would sell for.
  • A real estate agent will provide a free Comparative Market Analysis based on recent sales of similar homes in your area.
  • A professional appraiser charges $300 to $500 but produces a formal document that banks and courts will accept as evidence of value.
  • Different methods often produce different numbers; this is expected because they measure different things or use different data.

What online estimates actually measure

Zillow, Redfin, and similar sites use public records (deed transfers, tax assessments, mortgage data) and their own algorithms to estimate value. They do not send anyone to your house. The estimate updates when nearby homes sell or when you update your home's details on the site.

These tools are useful for a rough sense of your home's ballpark value and for comparing your neighborhood to others. They are less reliable if your home has unique features (a finished basement, a pool, a recent major renovation), if your neighborhood has few recent sales, or if your home is very new or very old. The margin of error can be 5 to 20 percent or wider in thin markets.

Zillow publishes its own accuracy data: its estimates are within 5 percent of actual sale price about 50 percent of the time nationally, but this varies by region. You can see Zillow's stated accuracy for your specific zip code on their website.

How to read your assessor's record

Your county assessor values your property every one to three years (the interval varies by state) to set your property tax bill. You can find this record by visiting your county assessor's website and searching by address or parcel number. Some counties also let you search by owner name.

The assessed value you find will be lower than market value in most states because assessors use different methods than real estate markets do. A home worth $400,000 on the open market might be assessed at $300,000 for tax purposes. The assessed value is public record, and you can see what the assessor thinks your land is worth separately from what the building is worth.

If you believe your assessed value is too high, most counties allow you to file a formal challenge called an appeal or grievance. The deadline is usually 30 to 45 days after you receive your assessment notice. You will need to show evidence (recent appraisals, comparable sales, photos of needed repairs) that the value is wrong. This process is free but requires you to gather documents and sometimes attend a hearing.

Getting a free estimate from a real estate agent

A real estate agent will prepare a Comparative Market Analysis (CMA) at no cost. This document lists recent sales of homes similar to yours in your area, adjusts for differences (your home is newer, or has fewer bedrooms), and suggests a value range. Agents do this to convince you to list with them, so they have an incentive to be accurate — overpricing loses them business.

To get a CMA, contact two or three agents in your area and ask them to prepare one. You do not have to list your home or commit to anything. The agent will ask about your home's condition, recent upgrades, square footage, and lot size. A good CMA will show you the actual sales prices of comparable homes, not just list prices, because list price and sale price often differ.

The CMA is most useful if you are thinking about selling, because it reflects what buyers in your market are actually paying right now. It is less useful if you just want to know your home's value for insurance, refinancing, or estate planning — in those cases, an appraisal is more formal and more widely accepted.

When you need a professional appraisal

A professional appraisal is a formal document prepared by a licensed appraiser. Banks require one before they will refinance or issue a home equity loan. Courts may require one in divorce or estate disputes. Insurance companies sometimes order one if you are insuring a high-value home.

An appraisal costs $300 to $500 depending on your home's size and location. The appraiser will visit your home, measure it, photograph it, inspect its condition, and research recent sales of comparable homes. The final report includes the appraiser's opinion of value, the method used, and the comparable sales data that supports it.

Appraisers are licensed by the state and must follow the Uniform Standards of Professional Appraisal Practice (USPAP). This means the appraisal is defensible in court and acceptable to lenders. If you disagree with an appraisal, you can request a second opinion, though the second appraisal will also cost a fee.

Why different sources give different numbers

An online estimate, an assessor's value, a real estate agent's CMA, and a professional appraisal can all be different — and all be correct for what they measure. An online tool uses an algorithm; an assessor uses tax law; an agent uses recent market sales; an appraiser uses the same sales data but applies professional judgment and visits the home.

Your home's value also depends on the purpose. For property taxes, the assessed value matters. For a mortgage or refinance, the appraisal matters. For selling, the market value (what a buyer will pay today) matters. For insurance, replacement cost matters — what it would cost to rebuild, not what the land and structure would sell for.

If you are seeing a wide range of estimates, check whether the sources are measuring the same thing. An online estimate that includes land value will be higher than an assessor's value that only values the structure. An appraisal done in winter may be lower than one done in spring if your neighborhood is seasonal. These differences are not errors; they reflect different methods and purposes.

Using property value information for decisions

If you are refinancing, use the appraisal your lender orders — that is the number the lender will accept. If you are selling, get a CMA from a local agent because it reflects current market conditions in your area. If you are checking your property tax bill, look at your assessor's record and understand that it is intentionally different from market value.

For insurance purposes, contact your insurance company and ask what value they use. Some use replacement cost (what it would cost to rebuild), others use market value. For estate planning or divorce, a professional appraisal is the safest choice because it is defensible and widely accepted.

Keep in mind that property values change. An estimate from two years ago is outdated. If you need a current value for any important decision, get a fresh one — whether that is a new online search, a call to your assessor's office, or a new appraisal.

Frequently Asked Questions

Is the assessed value the same as market value?

No. Assessed value is used to calculate property taxes and is usually lower than market value. Market value is what a buyer would pay for your home today. They are calculated differently and serve different purposes. Your assessor's record is public, but it does not tell you what your home would sell for.

Can I use an online estimate to refinance my home?

No. Lenders require a formal appraisal by a licensed appraiser. Online estimates are useful for your own information, but banks will not accept them as proof of value for a loan. You will need to pay for an appraisal if you want to refinance.

How often should I check my property's value?

If you are just tracking it for your own knowledge, once a year is reasonable. If you are planning to sell, get a fresh CMA from an agent a few months before you list. If you are refinancing or applying for a home equity loan, the lender will order a new appraisal, so you do not need to get one yourself first.

What if my online estimate seems way too high or too low?

Online estimates can be off by 5 to 20 percent or more, especially in areas with few recent sales or homes with unusual features. Check whether the estimate includes land value or just the building. Look at the comparable sales the tool used — if they are not similar to your home, the estimate will be less accurate. A CMA from a local agent is more reliable.

Do I need an appraisal just to know what my home is worth?

No. An appraisal costs money and is mainly useful when a lender or court requires it. For general knowledge, an online estimate or a free CMA from an agent will give you a reasonable ballpark. An appraisal is worth the cost only if you need a formal, defensible document.