Size Systems in Google Shopping Feeds

In a Google Shopping feed, the size_system attribute tells Google which country's sizing a product's size value uses, such as US, UK or EU. Send it whenever you send a size, and make it match the label shoppers see on your product page.

This guide is for store owners and developers who manage feeds for WooCommerce, Wix or custom stores. The same size data also powers on-page tools, as in our overview of virtual try-on for WooCommerce. Google's rules below were checked on its Merchant Center Help pages in November 2026. Confirm them again before you change a live feed.

What does the size_system attribute do?

It labels the sizing convention behind your size value. A "10" means something different in the US, UK and Australia, so Google needs to know which one you mean.

Google's size system page says the attribute is optional for each product. It also says that if you submit a size, you should also submit the size system. It recommends sending it for all apparel products.

If you leave it out, Google uses the standard system for your target country. That default is often fine, but it can be wrong for brands that label in another system.

Which values can you send?

The same page lists the accepted values. They are AU, BR, CN, DE, EU, FR, IT, JP, MEX, UK and US.

Value	Country or region
US	United States
UK	United Kingdom
EU	European Union
AU	Australia
DE, FR, IT	Germany, France, Italy
BR, MEX	Brazil, Mexico
CN, JP	China, Japan

Use the values exactly as Google lists them. The page also says you must follow its formatting guidelines, or the information can't be used.

Which size system should match your target country?

For apparel, Google's size attribute page says the country you pick for size system should match the target country. A feed that targets the United States but labels sizes in the UK system is a mismatch to avoid.

If you sell in more than one country, create a feed per target country. Each can carry that country's size system and labels.

How do you map your sizes in the feed?

Think of mapping as three steps: decide the label, decide the system, and keep both identical on the page.

1. Pick the labels you show shoppers. If your page says "UK 12", the feed size should say 12 and size_system should say UK.
2. Pick one system per feed. Don't mix systems inside one feed for one target country.
3. Check letter sizes. Labels like S, M and L aren't tied to a country, but the system value still helps Google interpret them.
4. Check the page. Compare three random feed rows with the live product pages.

Some stores sell internationally with a UK, US and EU conversion chart. That is a good idea on the page. In the feed, still choose one system for each target country and keep conversions on the product page.

What mistakes should you avoid?

Most feed problems with sizes come from a few repeat errors:

• Mixing systems. Some rows say UK and others say US for the same target country.
• Leaving the value out. Google then assumes the standard system for the target country, which may not be yours.
• Putting the system in the size value. Keep the label, such as 12, in size and the country, such as UK, in size_system.
• Changing page labels without the feed. If you rename sizes on the product page, update the feed too.
• Listing a range in one value. Google says to use a slash, not commas, and to submit variants as separate products.

Run a small test after each change: pick a few products and compare the feed row with the page.

What about size type and unusual cuts?

Size system is about the country. Size type is about the cut. Google's size page says that if a product fits a specific group, such as petite, oversize or maternity, you should submit the size type. Its examples use oversize and regular.

Google doesn't list every allowed size type on that page, so check the current help page before using a value.

For deeper background on how other marketplaces treat charts, see Amazon fashion size charts for sellers. For the attributes around size, including gender and age group, read Google Merchant Center apparel attributes.

How does this connect to on-page sizing?

A clean feed brings the right shopper to the right size. Then the product page has to confirm it. If the feed says US and the page shows a European chart, you have created friction.

ZeDaq.ai lets you enter your own size chart for each garment type and recommends your own labels from a body scan of one photo plus height. If you haven't added a chart, it falls back to a generic UK, US, EU or AU chart. Keeping your feed labels and chart labels the same means the two systems agree.

If you run Shopify, read Google Shopping for Shopify clothing stores for the Shopify side of feed setup.

FAQs

Is size_system required?

No. Google's page marks it optional, but it recommends sending it for all apparel and says to send it whenever you send a size.

What happens if I skip size_system?

Google uses the standard sizing system for your target country. That works only if your labels follow that system.

Can one product have two size systems?

Google says to submit one size per product, and the first is used if you send several. Create a separate feed per target country if you need different systems.

Where do I check the current accepted values?

Use Google's size system help page. This article reflects it as checked in November 2026.