Shoe size "Footwear - Sizing - Vocabulary and terminology"; currently in development are companion standards ISO/TS 19409 "Footwear - Sizing - Measurement of last dimensions" and ISO/TS 19410 "Footwear - Sizing - Inshoe measurement". The adult shoe sizes are calculated from typical last length, which is converted from foot length in mm by adding an allowance of two shoe sizes: where formula_13 is foot length in mm. Direct conversion between adult UK, European and Mondopoint shoe size systems is derived as follows: Exact foot lengths may contain repeating decimals because the formulas include division by 3; in practice, approximate interval steps of
ISO TC 279 number of observing countries. The secretariat of TC279 is the AFNOR (AFNOR), located in Paris, France. France has the secretary (AFNOR) and the chairmanship of this TC. Other organizations can participate as Liaison Members, some of which are internal to ISO/IEC and some of which are external. The external organizations that are in liaison with TC279 are: Work on the development of standards is done by working groups (WGs), each of which deals with a particular field. ISO TC 279 ISO TC 279 is a technical committee of the International Organization for Standardization (ISO). Its purpose is to develop, maintain