What Size Is WMS, WX, OS? - Nylon Nostalgia

Vintage sizes such as 'WMS', 'WMNS', 'WX', 'OS' and 'XOS' can be difficult to understand these days and the actual sizes varied quite a bit between manufacturers. A vintage sizing comparison chart like the one below can only give approximate guidance. Therefore my advice would be to use this vintage system of clothing sizing as a very rough guide only and use the actual measurements of each garment instead - only that way can you be absolutely sure of accuracy.

I have compiled the following explanation of the meaning of each size, which I hope you find useful.

• SW size means 'Small Women's'
• W / WMS size means 'Women's' (Standard)
• WMNS also means 'Women's', which is the same as WMS.
• WX size means 'Women's Extra'
• OS size means 'Outsize'
• XOS size means 'Extra Outsize'
• XXOS size means 'Extra Extra Outsize'

Fact: sizes WMS and WMNS were often shown with an apostrophe , for example WM'S and WMN'S. Both refer to the word 'women's' of course. Sometimes, WMS and WMNS standard size were described simply as Women's in advertising.

On 19 July 1946, the UK Board of Trade made a ruling that from that date all women's underwear sizes will be marked by numbers instead of letters in the hope that label sizes would be clearer and easier to understand. The letters OS and WX could still be used on 'outsize' ladies underwear provided they were accompanied by numbers as well. This ruling is important to anyone who wants to date vintage women's underwear because use of the old 'WMS', 'WX', 'OS' etc Alpha system would be manufactured no later than 1946. A little word of warning is due at this point though because I have seen clothing advertisements showing the old Alpha system as late as 1949, 1950 and even 1966, which strongly suggests manufacturers and retailers were reluctant to change for fear of confusion in the eyes of consumers.

Acceptance of the 1946 change over to a numerical system of clothing sizing was definitely slow for the female British consumer. Four years later in 1950, a member of the Drapers' Chamber of Trade Executive Council is on record as saying "The public do today as they have always done. They go around asking for W, SW and WX sizes. That is what they understand, and they don't want anything else". In 1953, the British Standards Institution were still trying to get over 30 clothing industry organisations to decide on a common numerical system of sizing, as had already been done successfully in America. Agreement on a standardised numerical sizing system in the UK was finally reached in 1954.

British made garments displaying the same size regularly had a margin of error of up to 2 inches until 1951 when the BS1445 standard was introduced in order to inspire trust and confidence in sizing for shoppers.

One of the reasons this archaic and confusing system of sizing clothing was eventually discontinued was that women with a fuller figure understandably resented being described as "extra outsize" (XOS) or "outsize" (OS) when buying clothes in shops.

To make matters even more confusing still there was a similar but different system in use in mid-century Australia that appears to be finer than the British system and used terms such as XSSW, SSW, SW, W, SOS, OS and XOS.

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This article was written by Emma Benitez, BA (Hons) in Fashion & Dress History, incurable vintage fashionista and the lady behind Nylon Nostalgia.

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