Or type coordinates
Click the map to place the first corner of your area.
Paste corner coordinates instead
One corner per line: latitude, longitude. Degrees and minutes work too (40°42′46″N 74°0′22″W).
Measured on the real shape of the Earth (WGS84), not on flat map pixels. Your shapes stay in this browser. The map pictures come from OpenStreetMap, so the map server sees which area you look at. Map data © OpenStreetMap contributors.
About the map area calculator
How many acres is that field? Find the place on the map, click around its edge, and this map area calculator shows the area in acres, hectares, square feet, square metres, km² and square miles. It also shows the perimeter — the length all the way round — and the length of each side.
The area is measured on the real shape of the Earth, not by counting pixels on the flat map. So a field in Canada and a field in Brazil are both measured right.
You can draw several shapes and get a total, drag the corners until they fit, and save the map with your drawing as a picture.
Features
- Click to draw — each click is a corner; three or more corners make an area
- Every unit at once — acres, hectares, m², km², sq ft and sq mi, plus the perimeter in feet, miles, metres and km
- Side lengths — each side of the shape gets its length on the map
- Easy to fix — drag a corner, drag a small dot to add a corner, right-click a corner to remove it, or undo
- Several shapes — draw more than one field and get the total, each in its own colour
- Paste coordinates — type or paste the corners from a survey or a GPS (one per line)
- Map picture — download a PNG of the map with your shapes, the areas and a scale bar
- Remembers your work — your shapes stay in this browser for next time
Area units
| Unit | Square feet | Square metres | Acres |
|---|---|---|---|
| 1 square foot | 1 | 0.0929 | 0.000023 |
| 1 square metre | 10.764 | 1 | 0.000247 |
| 1 acre | 43,560 | 4,046.86 | 1 |
| 1 hectare | 107,639 | 10,000 | 2.471 |
| 1 square kilometre | 10,763,910 | 1,000,000 | 247.1 |
| 1 square mile | 27,878,400 | 2,589,988 | 640 |
An acre is 43,560 square feet. An American football field without the end zones (300 × 160 feet) is 48,000 sq ft, or 1.10 acres. A hectare is a square of 100 × 100 metres.
Why a flat map would give the wrong area
Web maps use a projection that stretches places far from the equator. A square that looks the same size on the screen covers much less ground in Norway than in Kenya. That is why this tool does not count pixels. It measures each shape on the Earth's real shape (the WGS84 ellipsoid, the same one GPS uses), with the GeographicLib library.
The same tiny square of 0.001° × 0.001° shows the difference:
| Latitude | Area | Acres |
|---|---|---|
| 0° (equator) | 12,309.1 m² | 3.042 |
| 40° (New York, Madrid) | 9,481.6 m² | 2.343 |
| 60° (Oslo, Anchorage) | 6,216.7 m² | 1.536 |
The squares look the same on the map, but at 60° north the ground is half the size of the one at the equator.
Tips for an exact measurement
- Zoom in before you click. At high zoom one pixel is a few centimetres.
- Click the real corners. Curved edges need more corners — drag the small dots on each side to add them.
- The map is not a survey. Fences, hedges and roads on the map are drawn by volunteers and can be a few metres off. For buying or selling land, use the official survey or deed.
- Use your location when you stand on the land. The map jumps to where you are.
Frequently asked questions
How do I find out how many acres my property is?
Type your town, or tap "Use my location" while you are there. Zoom in until you see your lot, then click each corner of the lot. The area in acres appears under the map.
Is it accurate?
The maths is exact for the shape you draw — the numbers match GeographicLib and pyproj to the last digit shown. How close it is to the real land depends on how well you click the corners and on how exact the map is at that spot.
Can I measure a roof or a house?
Yes, you can draw around a building and get its footprint in square feet. A sloped roof has more surface than its footprint, so for roofing use the Roofing Calculator with the pitch.
Is there a satellite view?
No. The map is OpenStreetMap, which is a drawn street map. It shows buildings, fields, paths and many fences, but it is not a photo.
Is my drawing sent anywhere?
No. Your shapes stay in this browser. The map pictures (tiles) come from OpenStreetMap's servers, so they see which part of the world you look at — as with any online map.
Can I save the map?
Yes. "Download the map picture (PNG)" saves the map that is on the screen with your shapes, their areas, a scale bar and the OpenStreetMap credit.
Related tools
- Radius Map — draw a circle of any radius around a place
- Square Footage Calculator — area from length and width, room by room
- Acres to Hectares — convert land areas
- Fence Calculator — posts, rails and panels for a fence line
- GPS Coordinates — read the coordinates of any point on a map
- GPX Viewer — see a GPS track on a map with its distance
How to use it
- Type a city in Go to a city, tap Use my location, or type coordinates. Then zoom in on your land.
- Click the map at each corner of the area. Three or more corners make a shape.
- Read the area in the big number, and in every unit under it. Change Show the area in to pick the main unit.
- Drag a corner to move it. Drag a small dot on a side to add a corner. Right-click (or long-press) a corner to remove it.
- Click the first corner to finish, or press New shape to measure another area. The total of all shapes is shown.
- Press Download the map picture (PNG) to save the map with your shapes.
