Dear café, I don't know, whether this is the right place to ask, but I'll try :-) If I would like to know size of the list in the memory (after complete evaluation, e.g. deepseq). The type is [( Int, [([Int],[Int])] )]. So we have K tuples of the type (Int,[([Int],[Int])]) Each tuple has N tuples of the type ([Int],[Int]) and each of these lists M elements long (yes, both a are of the same length). Top level list needs (on 64bit CPU) 8 bytes for pointer to elements, 8 bytes to point to another element, some more "expenses", probably yes, tag, anything else? So we have K*(16+XXX), where XXX is for size of (Int,[([Int],[Int])]). Tuple needs 8 bytes for each pointer, so XXX = 16 + YYY, where YYY is the size of the [([Int],[Int])] list. It needs 8 + 8 bytes on the list, we have N such elements, thus YYY = N * (16 + ZZZ), where ZZZ is size of the ([Int],[Int]). Again tuple, so 16 bytes + 2*(M * (16 + 8)) -- 16 bytes for 2 tuple elements -- 2 for two lists -- every list 16 bytes for list itself -- 8 bytes for Int So ZZZ = 16 + 2*(M * (16 + 8)), thus YYY = N * (16 + 16 + 2*(M * (16 + 8))), thus XXX = 16 + N * (16 + 16 + 2*(M * (16 + 8))), thus size = K * (16 + 16 + N * (16 + 16 + 2*(M * (16 + 8)))) = K* (32 + N* (32 + M*48) ) Am I right? Roughly right? Or totally wrong? E.g. for K = 25, N = 10000, M = 7 we get cca 88MiB ? Why am I asking? In reality the memory consumption is much higher, so I must be missing some extras, e.g. each memory chunk extra 8 bytes for GC, extra for tag, extra to point to VMT? Regards, Dušan