Method for manufacturing a mattress having a predefined firmness with at least one layer (14, 16, 18, 20) to achieve a user-selected predefined firmness with low deviation, wherein the mattress has at least a first mattress component and a second mattress component, wherein the method comprises the following steps: a) providing at least a first block of foam and a second block of foam, b) determining the actual material properties of at least one region of the at least first block of foam and the second block of foam, in particular density, stress properties and/or strain properties, c) determining at least the sections and/or points of the first block of foam and of the second block of foam that will form the first mattress component and the second mattress component, respectively, of the same mattress, d) adapting a basic geometry of at least the first mattress component and the second mattress component to be cut off at least the first block of foam and the second block of foam, respectively, in dependence of at least the determined material properties of the corresponding section and/or points of the first block of foam and the determined material properties of the corresponding section and/or points of the second block of foam in order to achieve the user-selected predetermined firmness of the mattress, e) cutting at least the first mattress component off the first block of foam and the second mattress component off the second block of foam according to the respective adapted geometry to obtain the respective mattress component, and f) connecting at least the first mattress component and the second mattress component to form the mattress, characterized in that an identifier is assigned to at least each of the first mattress component and the second mattress component, wherein the identifiers of the first mattress component and the second mattress component that are intended for the same mattress are linked with one another, and wherein the mattress is formed using at least the first mattress component and the second mattress component having linked identifiers. a) providing at least a first block of foam and a second block of foam, b) determining the actual material properties of at least one region of the at least first block of foam and the second block of foam, in particular density, stress properties and/or strain properties, c) determining at least the sections and/or points of the first block of foam and of the second block of foam that will form the first mattress component and the second mattress component, respectively, of the same mattress, d) adapting a basic geometry of at least the first mattress component and the second mattress component to be cut off at least the first block of foam and the second block of foam, respectively, in dependence of at least the determined material properties of the corresponding section and/or points of the first block of foam and the determined material properties of the corresponding section and/or points of the second block of foam in order to achieve the user-selected predetermined firmness of the mattress, e) cutting at least the first mattress component off the first block of foam and the second mattress component off the second block of foam according to the respective adapted geometry to obtain the respective mattress component, and f) connecting at least the first mattress component and the second mattress component to form the mattress,