Measure land area with GPS or maps

It is useful for planning and field estimates. Accuracy depends on the device, sky view, signal conditions, and how points are collected. The app shows an uncertainty estimate (±), but it is not a legal survey.

GPS positioning works without an internet connection. Map imagery usually requires internet; previously cached imagery may sometimes remain visible, depending on the map provider. Centimeter-level RTK is the exception: its corrections arrive over the internet, so the phone needs a connection for as long as you measure, unless the receiver has a correction source of its own.

Tap the boundary corners on the map, use the fixed crosshair, or walk the boundary with GPS. The app calculates area, distance, and perimeter as you work.

Yes. Export a measurement or collection as PDF, DXF, KML, GeoJSON, or GPX for reports and use in other mapping tools.

No. Dipper is for planning, field notes, and estimates. For legal boundaries, construction, conveyance, or other high-stakes work, use a licensed land surveyor.

Walk the boundary with GPS, or tap the corners on satellite imagery. For a field boundary, averaged corner points typically land within a few metres — enough for seeding rates, fencing, spraying, or rent calculations. Hire a surveyor when the number has to hold up legally.

Trace the roof outline on satellite view to get the footprint area. Keep in mind that satellite imagery gives you the flat, top-down area: a pitched roof's actual surface is larger, so multiply by the pitch factor before ordering materials.

Measure the perimeter, not the area. Trace the boundary on the map or walk it with GPS — the app shows the total perimeter plus the length of every individual segment, so you can order per run and allow for gates.

Add as many boundary points as the shape needs; there is no limit. Place extra points along curves to follow them closely. If a pond, building, or excluded strip sits inside the parcel, use an interior cutout to subtract it and get the net area.

Four things worth checking: that you can export your own data without a subscription, that it reports an accuracy range instead of claiming centimetre precision, that GPS positioning works without mobile data or Wi-Fi, and that ads do not cover the map while you tap. Dipper does all four; some other apps do some of them.

A modern phone under open sky usually resolves to a few metres. Survey-grade RTK GNSS resolves to centimetres. That gap barely matters when estimating a ten-hectare field and matters enormously for a property line, which is why the app shows its own uncertainty range on every result.

With a suitable external RTK receiver, current corrections and a stable fixed solution, positioning can reach centimeter level. Connect the receiver over Bluetooth LE or Wi-Fi. When the app sends NTRIP corrections, the phone needs internet throughout the measurement; a receiver with its own correction source may not. Conditions and receiver setup affect accuracy. Phone GPS alone is generally meter-level. See the help center for setup and accuracy guidance.

Any receiver that outputs standard NMEA 0183 over Bluetooth LE or Wi-Fi (TCP). iPhones cannot use classic Bluetooth (SPP) receivers. For RTK, choose a multi-band receiver that accepts RTCM 3 corrections on the same connection; GST, GSA and GSV output add the accuracy estimate and the sky plot.

Many countries, states and provinces run government or university RTK networks (often called CORS), frequently free after registration: search for the RTK or CORS network in your region. Commercial RTK services sell monthly or yearly subscriptions, usually with wider coverage. You can also run your own base station. The service gives you a caster address, port, username and password to enter in the app. A base station within about 20–30 km gives the fastest, most reliable fix.