I have a GIANT 19 inch mattress and this mattress cover fit almost perfectly. I have struggled to find a cover that fit well and did not ride up showing half of the mattress or pop off at the corners when my adjustable frame was in use. I say it fit “almost perfectly” because it was a snug fit with no room to spare. The plush top is also really comfortable. I will definitely buy this one again as it was a reasonable price and well-made