Geo Calc – Polygon Area, Perimeter & Centroid

Choose this endpoint when you need accurate geodetic area, perimeter, and centroid calculations for a polygon on the WGS84 ellipsoid — particularly for land parcels, geographic boundaries, or GIS workflows requiring multi-unit output (m², km², hectares, acres) in a single call. Prefer this over flat-earth or simple Euclidean calculators when precision over curved Earth surfaces matters. Also useful when you need self-intersection validation or polygon orientation alongside the geometric measurements.

• Fewer than 3 vertices provided — returns invalid/error response
• Malformed points string (wrong delimiter, missing values) — parse error or 400 response
• More than 300 vertices submitted — rejected with validation error
• Self-intersecting polygon detected — flagged in response but may still return degraded results
• Antipodal or polar-spanning polygons may yield inaccurate spherical excess results
• Payment not included or insufficient — x402 payment required error