Centroid Calculator

If you're wondering how to find the centroid of a triangle or any other shape, look no further – this awesome centroid calculator is here for you.

One "x, y" pair per line, in order around the shape.
Clear
Area centroid(3, 2)the balance point of the filled shape
Vertex average(3, 2)equal masses at the corners
Area24
Vertices4

Vertices

#xy
100
260
364
404

The formula

centroid = the average of the vertex coordinates

Two different centroids

For a triangle these coincide, which is why the distinction is easy to miss. For anything else they differ: the vertex average treats the corners as equal point masses, while the area centroid is where a cut-out of the shape would balance. A long thin quadrilateral with two corners bunched together shows the gap clearly.

Area scales with the square

Double every length in a flat shape and the area quadruples; triple them and it grows ninefold. Perimeter, being a length, scales in step with the sides. That mismatch is why bigger shapes enclose proportionally more area per unit of edge — and why a circle, having no corners at all, encloses the most area for a given perimeter of any shape.

Units

Whatever unit you enter, the area comes out in that unit squared and the perimeter in the unit itself. The calculator is unit-agnostic — enter centimetres and read cm and cm², or feet and read ft and ft². Just do not mix units between fields.