What is the difference between a 90x210 and a 90x220 cm mattress?

A 90x220 cm mattress is 10 cm longer than the 90x210 and is designed for sleepers taller than 190 cm. Both the 90x210 and 90x220 prevent feet from hanging over the edge, but the 220 cm length is the right choice once you exceed 190 cm in height. If you are between 185 and 190 cm tall, the 90x210 is sufficient; above 190 cm, the 90x220 gives the margin your body needs.