The degree of firmness that a person finds comfortable depends very much on their preference. Nevertheless, there is a weight category for each degree of hardness that can be used as a guide. Many people find hard mattresses more comfortable than soft mattresses. Firmness levels are designated by manufacturers as H1 to H4, with H1 being the softest and H4 the hardest mattresses.
Certain manufacturers have also introduced other firmness levels. Nevertheless, H1 to H4 are the most common categories. To be orthopaedically correct, the spine should be optimally supported during sleep. The easiest way to do this is to seek advice from a specialist. However, there are rules of thumb here too. The following table shows which degree of firmness is optimal for which weight: