Size Values for Google Attributes

I just found this in Google's help pages as they relate to attributes and am posting it here for everyone's reference since I know the question about how we're supposed to enter apparel sizes has come up numerous times before:

Important:

• For variants, each different size or size combination must be submitted as a separate item, in conjunction with the 'item group id'. Visit submitting apparel products for more details.
• If sizes contain multiple dimensions, condense them into one value (e.g., “16/34 Tall” for neck size 16 inches, sleeve length 34 inches, and “Tall” fit).
• Use consistent size values across variants of the same product, as well as across multiple products of the same category. For example, within a group of t-shirts, use “S”, “M” , and “L” as sizes, not “S”, “Medium” , and “Lrg”.
• You may use the same image for size variants if specific images are not available but we recommend that the ‘link’ attribute leads to a page which specifies all the details about the variant item.
• The values you provide may be displayed to users, so provide values that they will be able to understand.
• You can provide additional details about your sizing in the text string. For US sizes, for example, you can provide “3.5 Kid” or “3.5 Toddler”.
• If your item is one size fits all or one size fits most, you can use the phrase 'one size', 'OS', 'one size fits all', ‘OSFA’, ‘one size fits most’, or ‘OSFM’ in this attribute.

Example Sizing Values

Sizing values can be difficult to represent across different types of apparel products. It is not required to provide these exact values, but it may be helpful for you to standardize the size values of your apparel products. You can also use the ‘size type’ and ‘size system’ attributes to provide more information about the sizing of your products.

Tops, Outerwear, and Dresses

• XXS, XS, S, M, L, XL, 1XL, 2XL, 3XL, 4XL, 5XL, 6XL
• 00, 0, 02, 04, 06, 08, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34

Bottoms

• XXS, XS, S, M, L, XL, 1XL, 2XL, 3XL, 4XL, 5XL, 6XL
• 00, 0, 02, 04, 06, 08, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34
• 23, 24, 26, 27, 28, 29, 30, 32, 34, 36, 38, 40, 42, 44
• For Pants: 24x30, 24x32, 24x34

Plus, Petite, Big, Tall, Inseams, etc.

• When an item applies to a special size group, like Plus, Petite, Maternity, or Big and Tall, use the ‘size type’ attribute.
• When an item includes an inseam, consider using this format for the size: 30 Short, 30 Regular, 30 Long

Shoes

• For US: 5, 5.5, 6, 6.5, 7, 7.5, 8, 8.5, 9, 9.5, 10, 10.5, 11, 11.5, 12, 12.5, 13, 13.5, 14, 14.5, 15, 15.5, 16. Note: When a shoe is available in different width sizes, an indication is recommended: 9.5 M, 8 W, 12 N.
• For Europe: 37, 38, 39, 40, 41, 42, 43, 44, 45

Source: support.google.com/merchants/answer/188494?hl=en