I have a purple queen 4" mattress, the description says the fitted sheet is 16" deep and even with how thick my mattress is, it's only 13". I thought the sheets would be deep enough but they don't even make it around the bottom of any of the corners. If I attempt for it to actually wrap around the bottom of the mattress then the other side pops off. If I settle for half on the corner then they all pop off during the night. Everything else is perfect, the fabric, the pattern, the color. But I wish the fitted sheet actually fit. Only buy these sheets if you have a skinny mattress!