Size charts / adidas to On size conversion

adidas to On size conversion

adidas and On sizes side by side for the same US size, men's and women's. The EU and UK labels come from each brand's own size chart. They compare size labels and do not assess product fit.

Size charts: adidas · On

Men's

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adidas and On men's sizes by US size
US	adidas EU	On EU	adidas UK	On UK
7	40	40	6.5	6.5
7.5	40 2/3	40 1/2	7	7
8	41 1/3	41	7.5	7.5
8.5	42	42	8	8
9	42 2/3	42 1/2	8.5	8.5
9.5	43 1/3	43	9	9
10	44	44	9.5	9.5
10.5	44 2/3	44 1/2	10	10
11	45 1/3	45	10.5	10.5
11.5	46	46	11	11
12	46 2/3	47	11.5	11.5
12.5	47 1/3	47 1/2	12	12
13	48	48	12.5	12.5
14	49 1/3	49	13.5	13.5

Women's

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adidas and On women's sizes by US size
US	adidas EU	On EU	adidas UK	On UK
5	36	36	3.5	3
5.5	36 2/3	36 1/2	4	3.5
6	37 1/3	37	4.5	4
6.5	38	37 1/2	5	4.5
7	38 2/3	38	5.5	5
7.5	39 1/3	38 1/2	6	5.5
8	40	39	6.5	6
8.5	40 2/3	40	7	6.5
9	41 1/3	40 1/2	7.5	7
9.5	42	41	8	7.5
10	42 2/3	42	8.5	8
10.5	43 1/3	42 1/2	9	8.5
11	44	43	9.5	9

Questions

Is a adidas EU size the same as a On EU size?: Not always. For 9 of 14 shared US men's sizes, the EU label differs. For example, US 10.5 is EU 44 2/3 at adidas and EU 44 1/2 at On.
What is a adidas US 10.5 in On?: At On, US 10.5 men's is EU 44 1/2 and UK 10. At adidas, it is EU 44 2/3 and UK 10.
Which sizes does the table cover?: Men's: US 7 to US 14 (14 sizes). Women's: US 5 to US 11 (13 sizes). The table shows only the US sizes that both charts list.
Does this table tell me how a shoe fits?: No. It compares the size labels of the adidas and On charts. Fit depends on the model; check the maker's guide for the model you want.