Free tool
Area and perimeter from coordinates
Paste the corner points of a boundary or outline in order. Get the area, perimeter and centroid.
Separate values with spaces, commas or tabs. A label before the easting and northing is allowed. Do not repeat the first point at the end; the polygon closes itself.
Method and limits
- Area uses the shoelace (surveyor's area) formula on the coordinates you give. The coordinates are used relative to the first point to avoid rounding loss with large grid values. The centroid is the centre of area of the polygon.
- Straight lines are assumed between points. This is a plane area on the grid, not a surface or ellipsoidal area, and no scale factor is applied. It is not a cadastral area: use the certified plan for legal areas.
- A check flags outlines that cross themselves. Checked against an independent geometry library on 300 random polygons (area, perimeter and centroid agree to rounding error) and 50 crossing outlines.
- This tool is a convenience, not a survey deliverable. Check results against your own work, and use certified methods for anything you sign off. Provided as is, in line with the terms. Nothing you enter is sent anywhere.