Under Armour to Allbirds Shoe Size Conversion

Switching from Under Armour to Allbirds? Under Armour runs small and Allbirds runs true to size, 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 up 0.5 moving to Allbirds

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

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

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

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

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

What is a Under Armour 10.5 in Allbirds?

A Under Armour 10.5 is about a Allbirds 10 — they share a foot length of roughly 27.5 cm (UK 9.5, EU 43.5).

Do Under Armour and Allbirds fit the same?

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

ⓘ Affiliate links below. As an Amazon Associate we earn from qualifying purchases at no extra cost to you.

★ Top pick · Recommended on Amazon

Allbirds Shoes

Shop Allbirds in your converted size.

View on Amazon →

Recommended on Amazon

Under Armour Shoes