Let be the number of squares that are required to cover the whole coastline and be the sidelength of one square of the mesh. Then the box-counting dimension is .

can be interpreted as the slope of a straight line in a plot of versus . To approximate this, take five points determined by five values of and compute the slope of the linear fit between those points. Smaller values for and higher map resolutions lead to a more accurate estimate, as can be verified by selecting a finer mesh from the menu. It has been computed that the box-counting dimension of the coastline of Great Britain is 1.25 by using a very fine mesh on a very detailed map. This Demonstration finds values up to 1.18 using mesh sizes and a map resolution compatible with a reasonable computing time.

A detailed description of the box-counting method used in this Demonstration can be found in [2].