This International Standard gives formulas, which allow analytical data relating to solid biofuels to be expressed on the different bases in common use. Consideration is given to corrections that may be applied to certain determined values for solid biofuels prior to their calculation to other bases. In the informative Annex A tools for integrity checks of analytical results are given. In the informative Annex B conversion factors for calculation into other units are given. The informative Annex C is a guideline for the use of validation parameters as can be found in ISO/TC 238 analytical standards.