Allbirds to Under Armour Shoe Size Conversion

Switching from Allbirds to Under Armour? Allbirds runs true to size and Under Armour runs small, so the size you order changes. Here's the full chart.

Reviewed by the 247Sizing teamLast updated: 12 August 2026

Under Armour runs 0.5 size larger than Allbirds, so you may need to size down when switching.

Size down 0.5 moving to Under Armour

Under Armour runs larger — order half a size smaller than your Allbirds size.

Find your Allbirds size on the left, read across for Under Armour:

Allbirds size	Under Armour size	UK	EU	Foot (cm)
6.5	7	5.5	37	23.5
6.5	7	5.5	37.5	23.9
7	7.5	6	38	24.3
7.5	8	6.5	38.5	24.7
8	8.5	7	39.5	25.1
8	8.5	7	40	25.5
8.5	9	7.5	41	25.9
9	9.5	8	41.5	26.3
9.5	10	8.5	42.5	26.7
10	10.5	9	43	27.1
10.5	11	9.5	43.5	27.5
11	11.5	10	44	27.9
11.5	12	10.5	44.5	28.3
12	12.5	11	45.5	28.7
12.5	13	11.5	46	29.1
13	13.5	12	47	29.5
13.5	14	12.5	47.5	29.9
14	14.5	13	48	30.3
14	14.5	13	48.5	30.7
14.5	15	13.5	49	31.1
15	15.5	14	49.5	31.5

⚠️ Fit varies by model. Allbirds runs true to size; half sizes are rounded, so go to the nearest whole. Under Armour tends to run about half a size small, especially in performance trainers.

Under Armour to Allbirds → · Allbirds chart · Under Armour chart · Brand finder

What is a Allbirds 10.5 in Under Armour?

A Allbirds 10.5 is about a Under Armour 11 — they share a foot length of roughly 27.5 cm (UK 9.5, EU 43.5).

Do Allbirds and Under Armour fit the same?

Not quite — Under Armour runs about 0.5 size larger than Allbirds.

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