KEVOS® MAKEOS · Geometry

Polygon Area and Centroid from Coordinates

What is the area, perimeter and centroid of this polygon from its corner coordinates?

Area (shoelace formula), perimeter and centroid of any simple polygon with up to eight corners, including irregular quadrilaterals (trapeziums) and plate outlines.

Open the calculatorRuns in your browser. No account needed.

How this tool works

Inputs, units and where to find them

InputUnitTypical source
Number of cornerscornersHow many of the listed corners are used (the first n), in order around the outline.
Corner 1
XmmX coordinate of corner 1.
YmmY coordinate of corner 1.
Corner 2
XmmX coordinate of corner 2.
YmmY coordinate of corner 2.
Corner 3
XmmX coordinate of corner 3.
YmmY coordinate of corner 3.
Corner 4
XmmX coordinate of corner 4.
YmmY coordinate of corner 4.
Corner 5
XmmX coordinate of corner 5.
YmmY coordinate of corner 5.
Corner 6
XmmX coordinate of corner 6.
YmmY coordinate of corner 6.
Corner 7
XmmX coordinate of corner 7.
YmmY coordinate of corner 7.
Corner 8
XmmX coordinate of corner 8.
YmmY coordinate of corner 8.

Method and formulas

  1. Area = ½ |Σ (xᵢ yᵢ₊₁ − xᵢ₊₁ yᵢ)| (shoelace formula).
  2. Centroid x̄ = Σ (xᵢ + xᵢ₊₁)(xᵢ yᵢ₊₁ − xᵢ₊₁ yᵢ) ÷ 6A, and similarly for ȳ (signed A).
  3. Perimeter = sum of side lengths.
  4. Example: the default quadrilateral has an area of 6,350 mm² with its centroid at (60.919, 28.976).

Limitations

  • Simple polygons only: sides must not cross each other.
  • Straight sides; arcs need their own segment areas added or subtracted.
  • Example values are illustrations. Replace them with values for your actual task.

Typical uses

  • Find the area and centroid of a plate or gusset
  • Calculate the area of an irregular quadrilateral
  • Check CAD areas

Who it is for

  • Design engineers
  • Toolmakers
  • Estimators

What you get

  • Area
  • Perimeter
  • Centroid
  • Direction of the corner order

Interpreting the result

  • List corners consecutively around the outline, either direction.

References

  • Machinery’s Handbook, 29th edition (Industrial Press, 2012), printed pp. 40–48, 66–76. Topic reference; no source tables or recommended settings are reproduced.

WORKOS tools are screening and decision-support utilities. Verify important financial, engineering, safety, legal or operational decisions using appropriate professional standards and your organisation’s approved data.

Open the Polygon Area and Centroid from Coordinates calculator