Size charts / ASICS to On size conversion

ASICS to On size conversion

ASICS 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: ASICS · On

Men's

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ASICS and On men's sizes by US size
US	ASICS EU	On EU	ASICS UK	On UK
7	40	40	6	6.5
7.5	40 1/2	40 1/2	6.5	7
8	41 1/2	41	7	7.5
8.5	42	42	7.5	8
9	42 1/2	42 1/2	8	8.5
9.5	43 1/2	43	8.5	9
10	44	44	9	9.5
10.5	44 1/2	44 1/2	9.5	10
11	45	45	10	10.5
11.5	46	46	10.5	11
12	46 1/2	47	11	11.5
12.5	47	47 1/2	11.5	12
13	48	48	12	12.5
14	49	49	13	13.5

Women's

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ASICS and On women's sizes by US size
US	ASICS EU	On EU	ASICS UK	On UK
5	35 1/2	36	3	3
5.5	36	36 1/2	3.5	3.5
6	37	37	4	4
6.5	37 1/2	37 1/2	4.5	4.5
7	38	38	5	5
7.5	39	38 1/2	5.5	5.5
8	39 1/2	39	6	6
8.5	40	40	6.5	6.5
9	40 1/2	40 1/2	7	7
9.5	41 1/2	41	7.5	7.5
10	42	42	8	8
10.5	42 1/2	42 1/2	8.5	8.5
11	43 1/2	43	9	9

Questions

Is a ASICS EU size the same as a On EU size?: Not always. For 4 of 14 shared US men's sizes, the EU label differs. For example, US 9.5 is EU 43 1/2 at ASICS and EU 43 at On.
What is a ASICS US 9.5 in On?: At On, US 9.5 men's is EU 43 and UK 9. At ASICS, it is EU 43 1/2 and UK 8.5.
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 ASICS and On charts. Fit depends on the model; check the maker's guide for the model you want.