What size is UGG US 11 in Crocs?

About Crocs US 10.5 (EU 44.5), matched by ~27.8 cm. Then adjust for the specific model.

Is a UGG 11 the same as a Crocs 11?

Not always. Labels can map to different foot lengths — use cm, then model fit.

Brand-to-brand size at a fixed US label — matched by foot length (cm), not guesswork.

UGG US 11 maps to about 27.8 cm on that brand’s chart. The nearest Crocs row at that length is US 10.5 / EU 44.5.

Same chart cm can still feel different on foot. Read the guides:

UGG: Classic Mini (true to size) · Classic Short II (true to size) · Tasman Slipper (true to size) · Classic Ultra Mini (true to size)

Crocs: Classic Clog (runs wide) · Echo Clog (true to size)

What size is UGG US 11 in Crocs?: About Crocs US 10.5 (EU 44.5), via ~27.8 cm.
Where is the full size table?: UGG to Crocs compare.