Online calculator to calculate the area of a non-self-intersecting irregular polygon with n vertices given by their Cartesian coordinates. The figure below shows an example of an irregular polygon with 6 vertices.
How to use the calculator
Enter the number of points n that form the irregular polygon and the coordinates x and y of the vertices and press "calculate area". The vertices coordinates must be input in order: either clockwise or anticlockwise. The output is the area of the irregular polygon. In case you have a polygon with more than 10 vertices, divide it into smaller polygons find the area of each polygon and add them to obtain the total area.