Many sand spits are morphodynamically complex cases that are hard to quantify. Therefore, most case studies on sand spits in a specific type of environment, are descriptive or even non-existent. As is the case for spits in low-energy lake environments, like the two spits at the Marker Wadden islands. Because quantification is necessary for spits in such complex environments, sedimentation was quantified around both spits using polar coordinates and morphologically simplified elevation levels around the spit-platform. It was found that, sediment rich currents that pass over the spit-platform boundary at a certain direction drive spit-platform growth in that direction. The spit-platform growth in turn dictates the growth of the emerged spit. Spit growth quantification enables a detailed understanding of the Marker Wadden spits, which gives insights in spit behaviour in low-energy lake environments. The quantification of spits in other environments could be a powerful tool for the understanding of spit behaviour.