ASICS to Karhu shoe size

The short answer

ASICS 11.5 is Karhu 11 or 12 by the two brands' own charts. 2 of 14 ASICS sizes land on a different label at Karhu.

At least one of the two brands publishes no foot length, so the rows line up the US size both charts print. Treat it as the label conversion, not a fit.

Every ASICS size read across to Karhu. US women's sizes on the left, US women's on the right.
ASICS	ASICS builds it for	Karhu, by chart	Same label	Karhu builds it for	Karhu also prints
4	foot length 21.5 cm	not made	not published	not published	not published
4.5	foot length 22 cm	not made	not published	not published	not published
5	foot length 22.5 cm	not made	not published	not published	not published
5.5	foot length 22.8 cm	not made	not published	not published	not published
6	foot length 23 cm	6	not published	not published	UK 4 · EU 37
6.5	foot length 23.5 cm	6.5	not published	not published	UK 4.5 · EU 37.5
7	foot length 24 cm	7	not published	not published	UK 5 · EU 38
7.5	foot length 24.5 cm	7.5	not published	not published	UK 5.5 · EU 39
8	foot length 25 cm	8	not published	not published	UK 6 · EU 39.5
8.5	foot length 25.5 cm	8.5	not published	not published	UK 6.5 · EU 40
9	foot length 25.8 cm	9	not published	not published	UK 7 · EU 40.5
9.5	foot length 26 cm	9.5	not published	not published	UK 7.5 · EU 41.5
10	foot length 26.5 cm	10	not published	not published	UK 8 · EU 42
10.5	foot length 27 cm	10.5	not published	not published	UK 8.5 · EU 42.5
11	foot length 27.5 cm	11	not published	not published	UK 9 · EU 43
11.5	foot length 28 cm	11 or 12	not published	not published	UK 9 · EU 43
12	foot length 28.5 cm	12	not published	not published	UK 9.5 · EU 44.5
12.5	foot length 28.8 cm	12	not published	not published	UK 9.5 · EU 44.5
13	foot length 29 cm	not made	not published	not published	not published

Tinted rows change label or sit between two sizes. 5 sizes have no counterpart on the Karhu chart. Read from the two charts only; no formula and no averaging.

What wearers say

Charts describe a garment. People who own both brands describe a fit, and their answer ranks above this table once five of them stand behind it. Pick your size in the converter to see whether there are enough yet.

Open in the converter Add an item you own

Sources

ASICS size guide, read on 2026-09-17. ASICS on TrueToSize
Karhu size guide, read on 2026-09-17. Karhu on TrueToSize

Karhu to ASICS