Spleen size is significantly influenced by body height and gender. The Splenocalc App is designed to calculate approximate percentiles of an individual´s spleen size. The algorithm of the Splenocalc App is based on the height- and gender-corrected normal values for homeostatic spleen length and volume (for women between 155 and 179 cm and men between 165 and 199 cm body height), the Splenocalc App is performing these calculations and is providing additional information.