Polygon Area Calculator
Find the area and perimeter of a polygon from its latitude/longitude corner points, in square meters, acres, hectares, square feet and more. Add points one by one, paste a list, or start from a preset.
Property
Agricultural
Parks
Sports Fields
Real Estate
Calculate property sizes and land valuations
Farm Planning
Measure field areas for crop and irrigation
Mapping
Areas outlined from map coordinates
What this area calculator does
Give the calculator the corner points of a shape — a plot of land, a field, a park or any other outline — as latitude/longitude coordinates, and it works out the area inside the shape and the perimeter around it.
The area is shown in square meters, square kilometers, acres, hectares, square feet, square yards and square miles, along with a few everyday comparisons such as soccer pitches and tennis courts.
Example
These four corners in Lower Manhattan (the "Rectangle" quick example):
40.7128, -74.0060 40.7148, -74.0060 40.7148, -74.0080 40.7128, -74.0080
| Area | 37,487.6 m² = 9.26 acres = 3.75 hectares |
|---|---|
| Perimeter | 781.9 m |
The shape is 0.002° tall and 0.002° wide, but it isn't square: at this latitude 0.002° of latitude is about 222 m, while 0.002° of longitude is only about 169 m. That's why areas have to be worked out on the globe, not from raw degrees.
How to use it
- Choose how to enter the shape: Point by Point to add points one at a time, Bulk Input to paste a list (one
latitude, longitudepair per line, up to 1,000 points), or Presets to try an example. - List the corners in order around the edge, clockwise or counter-clockwise. You don't need to repeat the first point at the end — the shape is closed automatically.
- Select Calculate Area to see the area, perimeter and unit conversions.
Coordinates in degrees, minutes and seconds, UTM or MGRS? Convert them to decimal degrees first with the coordinate converter. In most map apps you can tap and hold (or right-click) a spot to see its coordinates.
How the area is calculated
The calculator uses the spherical polygon area formula from Chamberlain and Duquette's Some Algorithms for Polygons on a Sphere (NASA JPL, 2007), also used by mapping libraries such as OpenLayers and Turf.js. With latitudes φ and longitudes λ in radians:
R is 6,371,007 m, the radius of a sphere with the same surface area as the WGS 84 ellipsoid. The perimeter is the sum of the great-circle (Haversine) distances along each edge. Unit conversions use exact definitions: 1 acre = 43,560 sq ft = 4,046.856 m², and 1 hectare = 10,000 m².
Accuracy and limitations
- Your points set the accuracy. Coordinates from a phone or a map click are often a few meters off, which matters more for small plots. A 5-meter error along one side of a 50 m × 50 m lot changes the area by about 10%.
- Not a legal survey. The Earth is modelled as a sphere and the ground as flat (no slopes). Results are fine for planning and estimates, but property boundaries and official acreage come from a licensed surveyor or your land registry.
- Points must go around the edge in order. If the edges cross each other (a "bow-tie" shape), the calculator asks you to reorder the points instead of returning a misleading number.
- Shapes around a pole aren't supported, and very large shapes (thousands of kilometers across) are better handled in GIS software.
Area units at a glance
| Unit | In square meters |
|---|---|
| 1 square foot | 0.0929 m² |
| 1 square yard | 0.8361 m² |
| 1 acre (43,560 sq ft) | 4,046.86 m² |
| 1 hectare (≈ 2.471 acres) | 10,000 m² |
| 1 square kilometer (100 hectares) | 1,000,000 m² |
| 1 square mile (640 acres) | 2,589,988 m² |
Frequently asked questions
How do I find the acreage of my land from GPS points?
Walk or click around the boundary and note the latitude and longitude of each corner, in order. Paste them into the Bulk Input box, one per line, and the result includes the area in acres. For curved boundaries, add more points along the curve.
Do I need to repeat the first point at the end?
No. The shape is closed automatically, and a repeated closing point (or a point accidentally entered twice in a row) is ignored.
Why is my result different from my property deed?
Deeds come from a survey of the actual boundary. Coordinates picked from a map or phone are less precise, the boundary may have curves you've simplified, and the deed may use a different measurement basis. Treat this calculator's result as an estimate.
Do you store the coordinates I enter?
Your coordinates are sent to the Orbit2x server to calculate the area, and the result is sent back to the page. They aren't saved, and you don't need an account. See the privacy policy for details.
Related tools
- Coordinate converter — convert DMS, UTM and MGRS to decimal degrees
- Distance calculator — distance between two points
- Midpoint calculator — the center of a group of points
- Unit converter — convert between other area and length units