C O N V E N T I O N A L S H O E S I Z I N G 4. To convert from IT/EU to UK|usM|usW the exact formula is UK|usM|usW = IT/EU ÷ 1.27 ─ 25|24|22½ however this does not produce an ending decimal. The more useful approach is to ÷1¼ but this offsets the size by ½ so increasing the bias number by ½ will produce UK sizing ending in odd 10ths and US sizing in ending in 5ths, both easily labeled using available character sets. This formula is: UK|usM|usW = IT/EU ÷ 1¼ ─ 25½|24½|23, providing a conversion accuracy of ±½mm for UK|usM|usW sizing from 2½|3½|5 to 10|11|12½. To convert from UK|usM|usW to IT/EU use IT/EU = 1¼ × (UK|usM|usW + 25½|24½|23) 5. Specifiing your foot length in mm is mondopoint sizing and to find your IT/EU sizing use: mm ÷ 6.35 For size 37IT: UK|usW = 37 ÷ 1¼ ─ 25½|23 = 4.1|6⅗ Last Length = 37 ÷ 1½ = 24⅔cm (9.71") mondopoint = 37 × 6.35 = 235mm (9¼") 37IT = 4 × 9¼" For size 40IT: UK|usM|usW = 40 ÷ 1¼ ─ 25½|24½|23 = 6½|7½|9 Last Length = 40 ÷ 1½ = 26⅔cm (10½") mondopoint = 40 × 6.35 = 254mm (10") 40IT = 4 × 10" For size 43IT: UK|usM = 43 ÷ 1¼ ─ 25½|24½ = 8.9|9.9 Last Length = 43 ÷ 1½ = 28⅔cm (11.29") mondopoint = 43 × 6.35 = 273mm (10¾") 43IT = 4 × 10¾" All calculations provide 5% toe room. For ~6⅔% toe room use ½ size larger. This document: https://www.amstzone.org/Home/ShoeSizing.txt For more information on sizing see: https://www.amstzone.org/Home/shoe-size-select-htmlcode.html JSG™ ©2022 All Rights Reserved. (CC BY─ND 4.0) creativecommons.org --- ↑ Post this info in forums where IT/EU sizing is disdussed. ↑ --- ↓ This additional info may also be posted. ↓ Rearrange paragraphs in numerical order and omit page break markers. --------------------------------------------------------------------- 1. In all sizing there should be at least 5% toe room. For a 10"/254mm foot (6½UK/9US/40IT) that would be ½"/12.7mm, 1½ UK|usM|usW and ~2 IT/EU sizes, and is also the amount used with the Brannock device. In Brazillian sizing a toe room of 2 sizes is subtracted from its IT size which is 0.525". With the Brannock device this toe room is the same for all sizes which increments the foot length by ⅙" for each ½ size instead of the conventional UK|usM|usW sizing incrementing the last or inside length by this ammount. One benefit of using 5% toe room allows even whole IT/EU sizes to align with Brannock system sizes making the device beneficial for incrementing the foot length by ⅛" for each ½ IT/EU size which corrolates with ⅜ size on the Brannock scale. The drawback to this is for a foot >10" the percentage of toe room deceases and for <10" it increases. Using 5% is a good standard and for shoes that have a toe box that has significantly less toe room for functionability purposes (pumps) they should be sized according to the reccomended foot lenght allowing for a each labeled size that is 5% less than the standard last measurement for that size. This is what should be considered to be Tru2Size. 2. In IT/EU sizing allowing 5% toe room equates to an increase in foot length per ½ size by ⅛" and to quickly find your size mulitiply your foot length in inches by 4 to get your size. This should be accurate if the model of shoe is TTS and is your normal width. For oxfords it is usually customary to use 6⅔% (⅔"@10") of toe room (2 sizes) especially for mens sizing and this will also give more width for a better fit if needed. If your width is different then you will need go to up/down in size it is wider/narrower. Going up/down by +1/─½ in size to accomodate a 1 width step adjustment is about the limit and if more adjustment is needed then choosing a wider/narrower width in that model if available is best, otherwise to find your correct size you should choose a model that offers your wider/narrower width. 3. The typical size conversion method used to convert from IT/EU to UK|US is to subtract 33|30 from IT/EU sizing. Since IT/EU uses the Paris Point (Metric) system and UK|US uses the Barleycorn (English) system this is not accurate and will produce a whole size error for the larger sizes. The standard difference between a UK and a usM|usW size is 1|2½ however in this conversion method it is 3 or sometimes 2. This means that a true size 6½|7½|9 in UK|usM|usW may be labeled as 7|8|10 so if you normally wear a 6½|7½|9 in a UK|usM|usW size but a model line that is manufactured on a IT/EU incremented last set that is labeled as 7UK/8usM/10usW/40IT would be your correct size. The IT/EU labelling being the most accurate so when buying IT/EU sized shoes learn your IT/EU size and use that instead. A 6UK/7usM/9usW/39IT would be ½|1 size smaller than your reccomended size. However most UK|usM|usW sizes use D|B widths as standard but some IT/EU sizes use E|C widths which may reduce size differences by up to ½ in some situations. In conventional last measurement the IT/EU system increments the UK|usM|usW system by ⅖ size and the UK|usM|usW system increments the IT/EU system by ⅝ size. For the Brannock system the IT/EU system increments it by ⅜ size and Brannock the system increments the IT/EU system by ⅔ size.