ST_Area¶

Introduction: Returns the spherical area of a geography in square meters, calculated on the sphere. The Earth is modeled as a sphere of radius R = 6 371 008 m (the authalic Earth radius); the result is the area of the polygon's interior on that sphere. Returns 0.0 for non-areal geographies (points, linestrings) and for NULL.

Multi-polygons sum the children's areas; geography collections recurse into their members.

ST_Area on a Geography on the sphere

The result is the area of the polygon's user-intended interior. If the input ring happens to be wound in the orientation that would describe the rest of the planet instead, Sedona returns the smaller of the two regions, so the answer is always bounded by half the surface of the Earth (~2.55 × 10¹⁴ m²).

If you specifically want the WGS84 ellipsoidal value (which is ~0.5 % lower for typical shapes), convert via ST_GeogToGeometry first and use the geometry overload:

SELECT ST_Area(ST_GeogToGeometry(geog), true) FROM …;

Format:

ST_Area (A: Geography)

Return type: Double

Since: v1.9.1

SQL Example

SELECT ST_Area(ST_GeogFromWKT('POLYGON ((0 0, 1 0, 1 1, 0 1, 0 0))'));

Output (in m²):

1.2364028804392242E10

That is approximately 12,364 km² — the spherical area of a 1°×1° box near the equator.