Overview

Amazon has rolled out a size‑normalization system that automatically builds the “Size” line on product detail pages from the underlying catalog attributes you already supply. The change went live this quarter and affects every marketplace, meaning sellers must ensure weight, dimensions, capacity and unit‑count fields are accurate. Because the displayed size is now generated by Amazon, any gaps or errors in those source fields can alter how shoppers perceive a product and, ultimately, impact sales.

Key Points

• Auto‑derived size values — Amazon no longer shows the free‑form text you type; it pulls weight, dimensions, capacity or unit count to create a uniform size line, e.g., a kettlebell listed with a weight of 32 lb appears as “32 lb” regardless of how you entered the text.
• Listing workflow unchanged — You still complete the same catalog fields during product creation or updates; the platform simply formats those values behind the scenes.
• Marketplace‑specific units — The system converts measurements to the units familiar to each region, such as ounces for the U.S. site and grams for the U.K., so the same ASIN can display different units without extra effort.
• Feed‑integrator compliance required — Third‑party feed solutions must adopt the new attribute standards; Amazon gave integrators roughly 60 days of notice before enforcing the rule.
• Higher conversion linked to clean data — Internal analysis shows ASINs with correctly formatted size information achieve noticeably higher purchase rates and gross merchandising sales.

How Size Normalization Works

1. Catalog attribute collection — Amazon reads the weight, dimensions, capacity, unit count and related fields you submit. Example: a coffee maker listed with a net volume of 1.5 L and a weight of 4 lb.
2. Attribute mapping per product type — Each category has a predefined set of attributes that feed into the size calculation. Example: for apparel, the system uses “size” and “fit” fields, while for hardware it relies on “item weight” and “dimensions.”