Dimensions Unit [dimensions_unit] Field for Product Feeds

Optional for ChatGPT

The dimensions_unit attribute defines the unit of measurement used for product dimensions such as length, width, and height.

While this field is optional, it becomes required whenever at least one dimension is provided.
It ensures that ChatGPT correctly interprets product size and avoids ambiguity between measurement systems.

This field is used exclusively by AI systems and does not affect how products are displayed on your website.

When to use

Use this field whenever you provide any of the following attributes:

• length
• width
• height

Without dimensions_unit, dimension values are considered ambiguous and may be ignored by ChatGPT.

• [dimensions_unit] accepts:
  • cm → Centimeters
  • in → Inches

Format

• Type: String
• Accepted values: cm, in
• Repeated field: No
• Schema.org property: Not applicable (AI-only field)

Examples:

Minimum requirements

Note: If at least one dimension is provided, dimensions_unit becomes mandatory.

• Provide dimensions_unit whenever length, width, or height is present.
• Use consistent units across all dimension fields.
• Do not mix different units within the same product.
• Do not provide dimension values without specifying the unit.

SEO / AI Tip

Accurate physical dimensions help AI systems:

• Compare similar products
• Filter results correctly
• Avoid incorrect size assumptions in conversational commerce

If you sell physical products, providing dimensions with a clear unit improves AI understanding and user trust, especially for items where size matters.

For best results, combine this field with:

• [length]
• [width]
• [height]
• [weight] and [item_weight_unit]

Official Source: ChatGPT Product Feed Specs