Every property has boundaries, but a surprising number of homeowners and landowners have only a vague idea of where those boundaries actually fall. Maybe you inherited a rural parcel and the corners were never clearly marked. Maybe you are planning a fence and do not want to accidentally build on your neighbor's land. Or maybe you are looking at buying a property and the acreage listed in the MLS does not quite add up when you look at it on satellite imagery.

Whatever brought you here, the good news is that the GPS in your iPhone or iPad has become a genuinely useful tool for measuring and documenting property boundaries. It will not replace a licensed surveyor for legal purposes, but for planning, estimation, and everyday reference, it can save you significant time and money. This guide walks you through the entire process, from understanding your deed to documenting your final measurements.

Why Knowing Your Property Boundaries Matters

Property boundaries are more than abstract lines on a map. They define what you own, what you can build, and what responsibilities you carry. Here are the most common situations where boundary knowledge becomes essential:

Disputes with Neighbors

Boundary disputes are among the most common causes of neighbor conflicts in the United States. They typically start small: a garden bed that creeps over the line, a driveway that appears to encroach, or a tree whose trunk straddles the boundary. Without clear knowledge of where the line falls, these situations can escalate from awkward conversations to expensive legal proceedings. Knowing your boundaries gives you facts to work with instead of assumptions.

Fencing Projects

Installing a fence is one of the biggest reasons people suddenly need to know their property lines. In most jurisdictions, a fence built even partially on a neighbor's property can be ordered removed at your expense. The standard advice from fencing contractors is to set your fence 6 to 12 inches inside your property line to provide a safety margin. But that only works if you know where the line is in the first place. Having a GPS measurement of your fence line measurement before you start digging post holes can prevent costly mistakes.

Building Setbacks

Nearly every municipality enforces setback requirements, which are minimum distances between structures and property lines. A typical residential setback might be 25 feet from the front property line, 10 feet from the sides, and 15 feet from the rear. If you are planning a shed, addition, detached garage, or even a deck, you need to know where your property line falls to calculate whether your project meets setback requirements. Building within the setback without a variance can result in stop-work orders, fines, or mandatory demolition.

Buying Land

When purchasing property, especially raw land or rural acreage, verifying the boundaries yourself provides an extra layer of confidence. Listing descriptions sometimes overstate acreage, and parcels in rural areas may not have been surveyed in decades. Walking the boundary with a GPS app before closing helps you confirm that what you are buying matches what you expect. It also helps you identify potential issues like encroachments, access problems, or terrain challenges that might not be obvious from paperwork alone.

Tax Assessment Verification

County assessors sometimes have inaccurate acreage on file, which directly affects your property tax bill. If you believe you are being taxed on more land than you actually own, having your own GPS measurement gives you a starting point for filing an appeal.

Understanding Your Deed Description

Before you head outside with your phone, it helps to understand how your property is legally described. Property deed descriptions in the United States generally follow one of three systems, and knowing which one applies to your parcel will help you interpret what you find.

Metes and Bounds

This is the oldest system, common in the eastern United States and anywhere land was settled before the rectangular survey system was established. A metes and bounds description reads like a set of directions: "Beginning at an iron pin on the north side of Oak Road, thence North 45 degrees East 200 feet to a concrete monument, thence North 30 degrees West 150 feet..." and so on until it returns to the starting point.

These descriptions can be challenging to follow because they reference compass bearings and distances, and sometimes reference physical features like trees, streams, or stone walls that may have moved or disappeared over the years. However, if you can identify even one or two of the referenced points on the ground, you can use them as anchors for your GPS measurement.

Lot and Block

Most suburban subdivisions use the lot and block system. Your deed simply says something like "Lot 14, Block 3, of the Oakwood Estates subdivision, as recorded in Plat Book 42, Page 17." The actual boundary lines and dimensions are shown on the recorded plat map, which you can typically obtain from your county recorder's office or, increasingly, find online. This system is straightforward because the plat map shows exact dimensions for every lot in the subdivision.

Section, Township, and Range

Used primarily in the western and midwestern United States, this system divides land into a grid. Descriptions look like "The NW 1/4 of the SE 1/4 of Section 12, Township 3 North, Range 7 West." Each section is one square mile (640 acres), and the fractional descriptions carve it into smaller pieces. A quarter of a quarter section, like the example above, is 40 acres. This system makes it relatively easy to estimate where your boundaries should fall on a map, since the grid is consistent and well-documented.

You do not need to become an expert in any of these systems. The key takeaway is that your deed description, combined with any recorded plat maps, gives you the official dimensions and shape of your property. Having that information handy when you go out to measure with GPS will help you verify that your on-the-ground measurement makes sense.

How to Find Your Property Lines Using County GIS

Before you set foot on the property, check whether your county offers free online GIS (Geographic Information System) mapping. The majority of U.S. counties now publish parcel data through web-based GIS portals, and these are incredibly useful as a starting reference.

What to Look For

Search for your county's name plus "GIS" or "property map" or "parcel viewer." Most county GIS systems allow you to search by address or parcel number and will show you an aerial photo overlaid with property boundary lines. You will typically be able to see:

Parcel outlines. The approximate shape and location of your property boundaries drawn on top of aerial imagery.
Acreage. The total area of the parcel as recorded by the county.
Adjacent parcels. Who owns the land next to you, which can be helpful if you need to discuss boundaries with neighbors.
Zoning information. Current zoning classification and sometimes setback requirements.
Flood zones and easements. Some GIS portals overlay FEMA flood maps and recorded easements.

Important Caveats

County GIS boundary lines are approximate. They are typically digitized from recorded plat maps and fitted onto aerial photographs, and the alignment can be off by 5 to 20 feet or more, especially in rural areas. Never assume that a GIS line is the exact legal boundary. However, GIS data is excellent as a reference layer. If your GPS measurement roughly matches the GIS outline, you can feel more confident. If there is a large discrepancy, it is a signal to investigate further.

Screenshot or save the GIS view of your parcel before heading out. Having it on your phone while you measure gives you something to compare against in real time.

Measuring Property Boundaries with GPS

Now for the hands-on part. Here is how to measure land area and boundary lines using the GPS in your iPhone or iPad with LandLens.

Step 1: Prepare Before You Go Outside

Gather your deed description, any plat maps, and your county GIS screenshot. Know approximately how many acres or square feet your parcel should be. Charge your phone fully, because GPS tracking uses significant battery. If your property is large, bring a portable charger.

Step 2: Check Conditions

GPS works best with a clear view of the sky. Heavy tree canopy, deep valleys, and proximity to tall buildings can reduce accuracy. If possible, measure on a clear day and avoid areas where dense foliage blocks the sky. Understanding GPS accuracy on phones will help you set realistic expectations for your measurement.

Step 3: Locate Physical Markers

Walk the property and look for existing boundary markers before you start recording. Common markers include iron rebar or pipes driven into the ground, concrete monuments with brass caps, wooden stakes, or survey flags. Use a metal detector if you suspect iron pins are buried under leaves or a few inches of soil. Finding even two or three corner markers dramatically improves the reliability of your measurement.

Step 4: Measure with LandLens

Open LandLens and select the area measurement tool. You have two approaches:

Manual pin placement works best when you can identify your property corners. Stand directly over each corner marker, wait 3 to 5 seconds for the GPS to stabilize, and then tap to place a pin. Move to the next corner along the boundary. If the boundary line is straight between corners, you only need pins at the corners. If it curves to follow a creek, road edge, or other natural feature, place additional pins along the curve to capture the shape.

GPS tracking mode is better when you cannot find clear corner markers but have a general sense of where the boundary runs. Start walking the perimeter and LandLens will automatically drop points as you move. Walk at a steady pace, slowing down around corners and curves so the tracking captures the shape accurately. This method is especially useful for large rural parcels where you might be following tree lines, fence rows, or other approximate boundary indicators.

Step 5: Close the Shape and Review

Once you return to your starting point, close the polygon in LandLens. The app will display the total area and perimeter. Compare the area to your deed description and county GIS data. If the numbers are within a few percent of each other, your measurement is likely a good representation of your actual boundaries. If there is a significant discrepancy, retrace the boundary paying closer attention to where you might have deviated from the actual property line.

Using Satellite Imagery to Verify Boundaries

One of the most practical ways to double-check your GPS measurement is to overlay it on satellite imagery. After you complete your boundary measurement in LandLens, you can view the polygon directly on the satellite map layer within the app.

Look for visual features that should align with your boundary:

Fence lines. Existing fences often follow property lines, though they sometimes drift over time. If your GPS boundary closely follows a visible fence line on satellite imagery, that is a good sign.
Mowed edges. In residential areas, the line between mowed lawn and unmowed grass often corresponds to the property boundary.
Driveways and walkways. These are usually built within property lines and can serve as visual reference points.
Tree lines and hedgerows. In rural areas, rows of trees or hedges were historically planted along property boundaries and many still mark those lines today.
Color changes in fields. Adjacent parcels with different crops or management practices often show a clear color difference on satellite imagery right at the property line.

If your GPS polygon lines up well with these visual features, you can be reasonably confident in your measurement. If the polygon cuts across features that should be entirely on your property, or misses areas that clearly belong to you, it is worth re-measuring or investigating further.

Understanding Easements and Right-of-Way

Your property boundaries define the outer limits of your land, but easements and rights-of-way can give other parties legal access to portions of it. Understanding these is critical before you make plans based on your boundary measurement.

What Is an Easement?

An easement grants someone else the right to use a specific part of your property for a specific purpose. Common examples include:

Utility easements. Power companies, water districts, and telecommunications providers often hold easements along property edges or through parcels. These easements allow them to install, maintain, and access their infrastructure. You typically cannot build permanent structures within a utility easement.
Drainage easements. These ensure that stormwater can flow across properties as designed. Building within a drainage easement can divert water and cause flooding on adjacent properties.
Access easements. If your property is landlocked or if a neighbor's driveway crosses your land to reach a public road, there may be a recorded access easement granting them the right to use that path.

What Is a Right-of-Way?

A right-of-way is similar to an easement but typically refers to the strip of land reserved for roads and public pathways. Your property might extend to the center of an adjacent road, but the right-of-way means you cannot use that portion. When measuring your usable land, keep in mind that the right-of-way reduces the practical area even if you technically own the land underneath it.

Easements and rights-of-way are usually recorded with the county and may appear on your deed, your title insurance policy, or your county GIS map. Check for these before assuming that your entire parcel is available for building or improvements.

Common Boundary Disputes and How to Avoid Them

Boundary disputes can be stressful, expensive, and damaging to neighbor relationships. Here are the most common types and how to prevent them.

Fence Line Disagreements

This is the single most common boundary dispute. One neighbor installs a fence, and the other neighbor believes it is on their property. Prevention is straightforward: measure your boundary with GPS before installing a fence, set the fence at least 6 to 12 inches inside your measured line, and communicate with your neighbor about your plans before construction begins. Having a documented GPS measurement from LandLens that you can share with your neighbor takes emotion out of the conversation and replaces it with data.

Tree and Vegetation Issues

Trees whose trunks straddle the property line are generally considered shared property. Trees on one side with branches extending over the line can be trimmed back to the boundary by the other property owner in most jurisdictions. These situations become contentious when expensive trees are involved or when one party removes vegetation the other valued. Knowing your exact boundary helps you understand your rights and responsibilities before making changes.

Encroachments

An encroachment occurs when a structure, driveway, landscaping, or other improvement crosses onto a neighbor's property. Sometimes encroachments are intentional, but more often they result from inaccurate assumptions about where the boundary falls. If you discover an encroachment during your GPS measurement, address it early. In many states, long-standing encroachments can eventually lead to adverse possession claims, where the encroaching party gains legal ownership of the disputed strip of land after a statutory period, typically 5 to 20 years depending on the state.

Prevention Strategies

Measure your boundaries when you move in, not when a dispute arises.
Document your measurements with GPS and save them for future reference.
Communicate with neighbors before starting projects near the boundary.
If you identify a potential issue, address it through conversation first, then mediation if needed, and legal action only as a last resort.

Different Types of Professional Surveys

If your situation requires professional accuracy, it helps to understand the different types of surveys available so you can request the right one.

Boundary Survey

This is the most common type for homeowners. A boundary survey locates and marks the corners and lines of your property based on the legal description in your deed. The surveyor will research historical records, locate existing monuments, take precise measurements, and set new markers where needed. This is what you need for resolving boundary disputes, planning construction near property lines, or confirming exactly what you own.

Topographic Survey

A topographic survey maps the elevation changes, slopes, and physical features on your property, including trees, structures, waterways, and utility infrastructure. It is typically required for larger construction projects, drainage planning, or site development. This survey does not focus on establishing boundary lines, though it often includes them for reference.

ALTA/NSPS Survey

Named after the American Land Title Association and the National Society of Professional Surveyors, an ALTA/NSPS survey is the most comprehensive and expensive type. It includes boundary lines, easements, encroachments, improvements, utilities, access points, and more. Lenders and title companies often require this type for commercial real estate transactions. Residential buyers occasionally need one for high-value properties or complex title situations.

Subdivision Survey

If you plan to divide your property into multiple parcels, you need a subdivision survey. The surveyor will create a plat map showing the new lot lines, dimensions, and any required dedications for roads or utilities. This plat must be approved by local government and recorded with the county. Subdivision surveys are among the most expensive because they involve extensive design work and regulatory compliance in addition to field measurement.

When GPS Phone Measurement Is Sufficient vs When You Need a Surveyor

The honest answer is that GPS phone measurement handles the majority of everyday situations, while professional surveys are necessary for anything with legal or financial consequences.

GPS Phone Measurement Is Sufficient For:

Estimating your acreage to compare against deed records or tax assessments.
Planning where to install a fence, with a reasonable safety margin set inside your line.
Verifying listed acreage before making an offer on property.
Documenting the approximate boundaries of land you manage for agricultural, forestry, or conservation purposes.
Creating reference maps for contractors, landscapers, or land managers.
Exploring and understanding the shape and extent of property you own or are considering purchasing.
Providing initial data to a surveyor to help them scope their work.

You Need a Professional Surveyor When:

A legal dispute over boundaries requires evidence that will hold up in court.
You are obtaining a building permit for construction near setback lines.
You are subdividing land into multiple parcels.
A title company or lender requires a survey for a real estate transaction.
You need to establish new boundary markers that will serve as permanent legal reference points.
An encroachment exists and you need documentation to resolve it.
Your property has a complex history with conflicting deed descriptions.

Think of it this way: if the outcome of your measurement might end up in front of a judge, a government official, or a bank, get a professional survey. If you are making practical decisions for your own planning purposes, GPS measurement from your phone is a highly effective tool.

How to Work with a Surveyor

If you determine that you need a professional survey, here is what to expect and how your GPS data can help.

Finding and Hiring a Surveyor

Look for a licensed land surveyor in your state. Your state's board of licensure for professional land surveyors maintains a directory, and many surveyors are also listed through the National Society of Professional Surveyors. Ask for references, confirm their license is current, and get a written quote before work begins.

Costs in 2026

Survey costs vary significantly by location, property size, terrain, and complexity:

Standard residential boundary survey: $400 to $900 for a typical suburban lot.
Rural boundary survey: $1,000 to $3,500 for parcels of 5 to 40 acres, depending on terrain and vegetation.
ALTA/NSPS survey: $2,000 to $6,000 or more, depending on property size and the number of optional table items requested.
Subdivision survey: $2,500 to $10,000 or more, depending on the number of lots and local regulatory requirements.
Topographic survey: $1,000 to $5,000, depending on the size and complexity of the site.

Costs tend to be higher in areas with dense vegetation, steep terrain, or limited access, since the surveyor's field crew spends more time on site. Properties with unclear or conflicting deed histories also cost more because the surveyor must invest additional time in records research.

How Your GPS Data Helps a Surveyor

Here is where your LandLens measurements become especially valuable. When you hire a surveyor, sharing your GPS boundary data gives them a head start. They can see what you have already measured, where you found existing markers, and where you think the boundary runs. This can reduce the time they spend on initial reconnaissance, which may lower your cost. You can export your data from LandLens in KML, GeoJSON, or Shapefile format, all of which surveyors and their GIS software can easily import.

What the Surveyor Will Do

A typical boundary survey involves four phases: records research (examining your deed, adjacent deeds, historical plat maps, and prior surveys), field work (locating existing monuments and taking precise measurements with survey-grade equipment), analysis (reconciling field measurements with the legal description), and deliverables (setting new monuments where needed and producing a signed plat or map). The process usually takes 2 to 4 weeks from start to finish, though it can be longer during busy seasons or for complex properties.

Documenting and Saving Your Boundary Measurements

Whether or not you end up hiring a surveyor, documenting your GPS boundary measurement creates a valuable record. Property boundaries do not change, so a measurement you take today remains useful for years or even decades.

Saving in LandLens

After completing your boundary measurement, save it with a clear, descriptive name such as "Property Boundary - 123 Oak Street" or "North Parcel - 40 Acres." Add notes about any corner markers you found, the date of the measurement, and the weather and sky conditions, since these affect GPS accuracy. Organize your boundary measurements into folders within LandLens to keep them separate from other measurements like garden beds, building footprints, or agricultural fields.

Exporting for Long-Term Records

Export your measurement in multiple formats for safekeeping:

KML for viewing in Google Earth, which lets you compare your boundary against satellite imagery from different dates.
GeoJSON or Shapefile for sharing with surveyors, appraisers, real estate professionals, or government agencies.
PDF report with the area, perimeter, coordinates, and a map snapshot, which serves as a portable reference document you can share with contractors, insurance companies, or anyone else who needs to understand your property boundaries.

Building Your Property File

Combine your LandLens export with other key documents to create a comprehensive property boundary file:

Your deed description and any recorded plat maps.
County GIS screenshots showing your parcel.
Your GPS boundary measurement export.
Photos of any corner markers you located.
Professional survey documents if you have one done later.
Notes about easements, rights-of-way, and any boundary agreements with neighbors.

This file becomes an invaluable resource any time a boundary question comes up in the future, whether you are planning a project, selling the property, or resolving a question with a neighbor.

The Bottom Line

Measuring your property boundaries with GPS is one of the most practical things you can do as a property owner. It gives you a clear picture of what you own, helps you plan projects with confidence, and provides a factual foundation for conversations with neighbors, contractors, and professionals. Tools like LandLens make the process straightforward: walk your boundary, record the measurement, and save it for reference.

For everyday planning and estimation, GPS measurement from your iPhone or iPad is more than adequate. For situations with legal or financial stakes, it serves as an excellent starting point that you can hand off to a licensed surveyor for professional-grade verification. Either way, knowing your boundaries puts you in a stronger position than guessing.