Overview

Amazon has launched a size normalization system that automatically standardizes how quantity and size information appears on product listings across search results and detail pages. The system pulls from existing catalog attributes — unit count, unit count type, and number of items — to create uniform, region-appropriate displays. For sellers, this change has direct implications for listing visibility, product comparability, and conversion rates.

What's Changing

• Standardized quantity formatting — Amazon now applies automatic normalization rules to display size and quantity data in a consistent format across all listings, replacing the previous patchwork of seller-entered formats.
• Geographic localization — Quantity values are converted to region-appropriate units automatically. US shoppers see ounces while UK shoppers see grams, without sellers needing to maintain separate listings per marketplace.
• Improved product comparison — Shoppers can now compare competing products side by side more easily, since quantities are displayed in uniform formats. Amazon says listings with valid quantity values see higher conversion rates.
• No manual action required for formatting — The normalization is fully automatic for listings that already have accurate catalog attributes populated.

How the System Works

Amazon's normalization engine reads three key catalog fields — unit count, unit count type, and number of items — then applies formatting rules to present the data uniformly. Two competing products listing the same supplement in different measurements, say 16 ounces versus 500 milliliters, will both display in the shopper's preferred local unit for easy comparison. The system handles all conversions behind the scenes.

However, the engine depends entirely on having accurate source data. If your listings are missing unit count or unit count type fields, normalization simply won't apply to your products, and they'll lose the display advantage that competitors with complete data will enjoy.

Why Catalog Attributes Now Carry More Weight

Amazon has stated that listings with properly formatted quantity information convert at higher rates. This is a significant signal that structured catalog data is becoming a bigger factor in how products perform on the platform. While Amazon hasn't explicitly confirmed that normalized quantity data feeds into search ranking or Buy Box algorithms, the conversion advantage alone makes it a competitive factor worth addressing.