This report gives a thorough description of the determination of two-dimensional areas and the estimation of area uncertainty. Considering the formulas for area determination, the basis is regular shapes, e.g. triangles, squares, rectangles, rhombi and regular (closed) polygons. The given formulas are valid as such; however, they also indicate how they can be simplified. The report presents strict as well as approximate formulas for area uncertainty estimates.          

The approach is mainly from a statistical point of view. However, there are some geometric factors/ variations which have an influence on the size of the area. They are dealt with by mathematical means.

In addition, less mathematical, more argument-based (philosophical) descriptions of other “areal defects”, having an influence on the area uncertainty, are presented. Examples of these defects are given to illustrate their impact on uncertainty estimation.

The report is mainly an English translation of an earlier Swedish report [1]. Therefore, some minor parts refer to Swedish conditions – e.g. regarding coordinate systems, map projections etc.