The height of our mattresses is an approximate measurement, as it is a product with a padded finish padding whose height may vary slightly. This can be a variation of +/- 1 cm. This is based on the European UNE-EN 1334 quality standard. This standard indicates that, when measuring mattresses, a tolerance of +/- 1 cm must be considered. Also, for mattresses that are sent rolled up, they may take a few hours to regain their height after being unpacked.