Capacity in drinkware is stated in fluid ounces for the US market and milliliters for most others, with 1 fl oz equal to about 29.6ml. Buyers who think in ounces still need the ml figure on EU packaging, so list both.

The common production ladder runs 12 / 17 / 20 / 32 / 40 / 64oz, though brands frequently adjust by a few milliliters for a specific look. These are nominal sizes, and actual filled volume can vary slightly with the lid and neck design.

oz	approx ml	Typical format
12	355	Travel mug, kids bottle
17	500	Travel mug
20	590	Tumbler
32	950	Large tumbler, sports bottle
40	1180	Large tumbler
64	1890	Growler

Sizing also shapes shipping economics, since a larger empty vessel takes more carton space and weight. A 12oz and 20oz SKU often sell together, so plan the ladder around what the buyer’s customers actually carry.

Practical takeaway: Standardize on a few sizes from the common ladder and print both oz and ml to serve both markets.