Finding Lot Size From an Address
Three free methods, ordered by reliability. Start at the top; drop down if the previous method doesn't have what you need.
Method 1: County GIS portal (most authoritative)
Almost every U.S. county publishes a public Geographic Information System (GIS) portal where anyone can look up parcel records by address. The data comes directly from the county assessor's office, so the lot sizes match what's on file for taxation purposes.
Search for "[your county] GIS" or "[your county] parcel viewer" on Google. Most look like a web map with a search box. Type the address, click on the highlighted parcel, and the sidebar will show recorded acreage, zoning, owner of record, and frequently the deed reference.
Caveats:
- Recorded acreage isn't always exact. Older parcels were measured with chains and rods. A modern survey might disagree by a few percent.
- Some rural counties only publish portions of their data. If the parcel viewer doesn't cover your address, move to method 2.
- Condos and HOA-governed lots may show the entire shared parcel, not your unit's footprint.
Method 2: Real estate listings (convenient, often correct)
Zillow, Redfin, Realtor.com, and similar listing sites display lot size on most properties, pulled from the same MLS data agents use. If the property has been listed for sale in the last decade or so, the lot size is almost certainly there.
The numbers are usually reliable, with a few caveats:
- Listing sites round to the nearest 0.01 or 0.1 acre. A "0.25 acre" listing could be 0.21 to 0.29.
- "Lot size" sometimes excludes shared common areas in PUD or condo developments.
- Older listings may have stale data if the lot was subdivided since.
If you don't see a listing because the property hasn't sold in years, type the address into Zillow anyway — they often have public records data even without an active listing.
Method 3: Direct satellite measurement
Sometimes neither GIS nor listing data is available — undeveloped land, recently subdivided parcels, properties in jurisdictions without public records, or properties outside the U.S. In those cases, you can measure the lot directly from satellite imagery.
The workflow:
- Open the calculator and search for the address.
- Zoom in until you can see fences, driveways, or other boundary markers clearly.
- Click "Draw Area" and trace the visible boundary.
- Read the area in acres.
For full details on the technique, including how to identify boundaries when they're not obvious, read how to measure property acreage from satellite imagery.
When the three methods disagree
You'll occasionally find that GIS, the listing, and your satellite measurement all give slightly different answers. That's normal. In rough order of trust:
- A current professional survey, if one exists. The deed will reference it.
- The county GIS, especially in counties with modern parcel data.
- The MLS / real estate listing for properties that have transacted recently.
- Your own satellite measurement, useful as a sanity check or when the others are unavailable.
For most everyday decisions — comparing properties, estimating fence costs, sizing a garden, ballparking taxes — any of these three is fine. For closing on land, refinancing, or anything legal, get a current survey.
A note on "lot size" vs "acreage" vs "land area"
These terms are usually interchangeable, but watch for two specific distinctions:
- Lot size is the platted parcel — what the deed describes.
- Land area sometimes excludes water bodies, easements, or rights-of-way.
- Buildable area is much smaller than lot size on properties with setbacks, conservation zones, or steep slopes.
If you're planning to build, "lot size" alone won't tell you what you can do. Check zoning, setback requirements, and any recorded easements separately.