It's not easy to take up - it has fairly short kick pleat at the back, which will be about 3 inches long if I take it up to teh right length.
M&S were famous for having stuff in different lengths. Now I actually want to buy soimething, they've stopped doing it.
Something knee length on a 5ft 9 model, is going to be an unflattering calf length on an average height woman.