Size conversions
Height, shoe, ring and clothing sizes, converted through the body measurement each size stands for, using the ISO, JIS and EN standards that define them.
Height Converter
Convert a height between feet and inches and centimetres, exactly, written as 5 ft 10 in rather than 5.83 ft, with the inches never rounding to 12.
Shoe Size Converter
Convert a foot length or a shoe size between US, UK, EU and Mondopoint sizes using the ISO 19407 conversion, with the nearest size and the sizes either side.
Ring Size Converter
Find a ring size from the inside circumference or diameter, exactly as ISO 8653 defines it, and convert between ISO and Japanese ring sizes.
Clothing Size Converter
Turn your bust or chest, waist and hip measurements into the EN 13402 size bands clothes are designated by, with the band each measurement falls in and the sizes either side.
Land Area Unit Converter (India)
Convert Indian land units, bigha, katha, guntha, cent, gaj, marla and kanal, to square feet, square metres, acres and hectares, using official state figures.
Sizes are measurements dressed up in local notation. Height is the clearest case: the inch has been exactly 25.4 millimetres since 1959, so feet and inches convert to centimetres with no approximation at all, and the one bug worth watching for is an answer of 5 ft 12 in, which should have carried into 6 ft. Shoe, ring and clothing sizes are harder, because each system counts in its own steps. ISO 19407 lines every shoe system up on foot length: Mondopoint counts it in 5 mm steps, UK sizes in 8.47 mm steps and EU sizes in 6.67 mm steps. A ring size under ISO 8653 is the inside circumference in millimetres, while Japan's JIS S 4700 counts inside diameter in steps of a third of a millimetre. A clothing size under EN 13402 is a band of chest, waist and hip measurements rather than a single number. The pages here convert through the measurement itself, never label to label, and when a measurement falls between two sizes they show the nearest one and the sizes either side instead of pretending the match is exact.