You will find the schematic drawing for each garment below the patterns. It will have all the measurement for each size we have in this pattern. If you follow the pattern and keep the tension/gauge the garment will have the same size as the schematic drawing.
If you think it is hard to decide what size to make, if can be a good idea to measure a sweater you have and like the size of. Then you can pick the size by looking at the schematic drawing and find the correct size there.
If your sweater is approx 60 cm/23½" in length, the chest circumference is 96 cm/37 3/4" and the hip circumference is 108 cm. Then this will be equivalent to size L in this schematic drawing.