Donum: Acreage Area Calculator

Donum measures a field the way you actually stand in it.

Open the map, tap the corners of your land, and the area appears at once — with the perimeter and the length of every edge. Or switch to Walk mode, keep the screen on and walk the boundary; Donum records the track and closes the shape for you.

FOUR WAYS TO MEASURE

• Area — tap the corners on the map and read the area instantly
• Distance — draw a line and get its length
• Point — mark and save a single location
• Walk — walk the boundary and let the phone draw it (PRO)

BUILT FOR REAL LAND

• Area is computed on the sphere, not on a flat sheet. On a large plot the flat formula is off by thousands of square metres — Donum does not take that shortcut.
• If your outline crosses itself, Donum tells you instead of quietly printing a wrong number.
• Every edge is labelled with its length, and corners are numbered.
• Drag a corner to fix it, tap a midpoint to insert one, long-press to delete.
• Type corners as coordinates, DMS, UTM or a map link if you cannot use the map. This is free.
• If the app closes before you save, your measurement is offered back the next time you open it.
• Walk mode has a minimum step and an accuracy threshold, so bad GPS fixes are dropped instead of bending your boundary.

UNITS THAT FIT YOUR COUNTRY

Square metre, hectare, dönüm (1000 m²), square kilometre, acre, square foot, square yard, square mile. Lengths in metres, kilometres, feet, yards or miles. Coordinates in decimal degrees, DMS or UTM.

SAVE AND EXPORT

Name a plot, give it a colour and a note, and it stays in your list with its area and date. Export as GeoJSON, KML for Google Earth, GPX, CSV for a spreadsheet, or a PDF report that includes a map of the plot — ready to print or send. Import KML, GeoJSON and GPX. A backup file of all your plots is free.

MADE TO BE READ OUTDOORS

A light theme for direct sun and a dark theme for early mornings. Three map layers: standard, topographic and a high-contrast one. The map is the screen itself — the readout sits in a sheet you can pull up or push down.

WORKS WITHOUT SIGNAL

Measuring and every calculation run on the device. Only the map tiles need a connection; the maths does not.

NO ACCOUNT, NO ADS, NO TRACKING

There is no sign-up, no login and no cloud. We run no server, so your plots, coordinates and location never reach us — they stay on your phone. There are no adverts and no analytics.

DONUM PRO

Area, Distance and Point modes are free, along with entering corners by coordinates, 5 saved plots, CSV export, copying coordinates and the backup file.

PRO unlocks Walk measuring, unlimited saved plots, KML/GeoJSON/GPX export, the PDF report, the topographic and high-contrast maps, plot colours and notes, plot groups, comparing a re-measured plot with its previous boundary, and a one-page plot card image. Plans, prices and any introductory offer are shown on the purchase screen before you pay. Subscriptions renew automatically; cancel any time in the Play Store.

HONEST ABOUT ACCURACY

Donum uses your phone's GPS. It typically drifts 3–10 metres, which is a few metres on a plot edge, and the app shows you your phone's own accuracy estimate rather than hiding it. This is NOT an official cadastral survey and cannot be used for title deeds, boundary disputes or legal work. For a legally binding measurement, use a licensed surveyor.

Map data © OpenStreetMap contributors.