Spagnoli, G. 2012. Comparison between Casagrande and drop-cone methods to calculate liquid limit for pure clay. Can. J. Soil Sci. 92: 859-864. During the construction of international projects off German coasts, it often occurs that clients and contractors work according to different standards. The aim of this experimental research is to compare the results of DIN and BS standards. The liquid limits of 50 pure kaolinitic and illitic clays were tested according to the German (Casagrande cup hard base) and the British (cone penetrometer) standards. Previous works were performed on natural clayey soils, while the research proposed in this work is based on tests carried out on standard pure clays. Illitic and kaolinitic clay types were chosen since they are abundant in the sediments of the Baltic Sea and North Sea where several offshore wind park projects are currently under construction or planned. The results show that the values obtained with the German Casagrande cup are slightly lower than those obtained with the British cone penetrometer. A regression equation was obtained to compare the liquid limit according to DIN and to BS for pure non-swelling clays namely LL_cone=0.99 LL_cup 1.05. The obtained relation agrees very well with other previous works.