Size Type [size_type] Field for Product Feed

Optional but recommended for relevant sizing filters

The size_type attribute indicates the cut or body shape for which a product is designed (e.g., petite, plus, tall). It helps shoppers refine searches and ensures your product appears in accurate size-based filters.

When to use

• Optional for all products.
• Recommended for apparel and accessories where the cut is relevant to fit.
• If not provided, Google defaults to regular, which may not be accurate for all products.

Supported values:

• regular
• petite
• plus
• tall
• big
• maternity

Format

• Type: Text (Unicode, ASCII recommended)
• Repeated field: Yes (maximum of 2 values)
• Schema.org property: Product.size — WearableSizeGroupEnumeration

File format examples:

You can submit 1 or 2 values if applicable (e.g., big, tall).

Minimum requirements

• Follow formatting rules and submit only supported values.
• If omitted, Google will default to regular.
• Do not submit custom or unsupported values (e.g., “oversized”).

Best practices

• Match the manufacturer’s specified size type.
• Use two values for dual size types (e.g., big, tall or petite, maternity).
• Pair with size_system to indicate the sizing standard (e.g., US, EU, JP).
• Always include the size and gender attributes alongside size_type for best filtering.

SEO Tip

Accurate size type data increases your product’s visibility in relevant filtered searches, ensuring the right customers see the right fit, which can boost conversion rates.

Official Source : https://support.google.com/merchants/answer/6324497