How do I convert Birkenstock shoe size to Altra?

Match by foot length in centimeters on each brand’s chart. Example: Birkenstock US 10 ≈ Altra US 10.0 (about 27.1 cm). Model fit can still differ — check model guides.

Is a Birkenstock US 10 the same as a Altra US 10?

Not always. Labels can map to slightly different foot lengths. Use the cm column, then adjust for the specific model’s fit.

Birkenstock to Altra size conversion

Match sizes by foot length (cm), then check model fit — US labels alone can mislead across brands.

Chart match · verify brand charts

Check current prices · Arizona Check current prices · Lone Peak 8

(paid link)

Your Birkenstock size (US)

Full converter (model + shoes you own) · Reverse: Altra → Birkenstock

Birkenstock → Altra chart

Static conversion table (crawlable). Interactive tool above uses the same cm matching.

Birkenstock US	cm	Altra US	Altra EU
6.0	23.5	6.0	38.5
6.5	24.0	6.5	39.0
7.0	24.5	7.0	40.0
7.5	25.0	7.5	40.5
8.0	25.4	8.0	41.0
8.5	25.9	8.5	42.0
9.0	26.2	9.0	42.5
9.5	26.7	9.5	43.0
10.0	27.1	10.0	44.0
10.5	27.5	10.5	44.5
11.0	27.9	11.0	45.0
11.5	28.4	11.5	45.5
12.0	28.8	12.0	46.0
13.0	29.7	13.0	47.5

Model fit matters

Even when charts match, lasts differ. Check these guides:

Birkenstock: Arizona · Boston

Altra: Lone Peak 8

Also compare Birkenstock to: Crocs

Check prices: Birkenstock Altra (paid link)

FAQ

How do I convert Birkenstock shoe size to Altra?: Match by foot length in centimeters on each brand’s chart. Example: Birkenstock US 10 ≈ Altra US 10.0 (about 27.1 cm). Then adjust for the specific model’s fit (runs big/small/narrow).
Is a Birkenstock US 10 the same as a Altra US 10?: Not always. Labels can map to slightly different foot lengths. Use the cm column, then check model guides on both brands.
Which direction should I read first?: Start from the brand you already wear, then open the model fit pages linked below — lasts differ even when charts match.

Clothes sizing uses a separate compare path.