Calculations in a prismatoid. A prismatoid is a polyhedron with two parallel polygons as base and cover faces, whose vertices are connected in a way, that the side faces are triangles or trapezoids (including parallelograms). If both parallel polygons have the same number of vertices and if the side faces all are trapezoids, this is a prismoid. The calculation of the volume is made with the height, the areas of base and cover face and the area of the cross section at half height. The difficulty is to get the latter. Enter four values and choose the number of decimal places, then click Calculate.

Formula:
V = h/6 * ( A_{1} + 4A_{2} + A_{3} )

This is a variation of the barrel formula of Kepler.

The height has a one-dimensional unit (e.g. meter), the areas have this unit squared (e.g. square meter), the volume has this unit to the power of three (e.g. cubic meter).