Dimensional Rating in Odoo – User Guide

Dimensional rating (also called dimensional weight) is a shipping cost calculation method used by carriers such as UPS and FedEx. It ensures that large, lightweight packages are billed based on the space they occupy, not just their actual weight. This prevents low-density items from taking up valuable space without fair compensation to the carrier.

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Why It Matters

Shipping cost discrepancies often occur when product dimensions or packaging details are inaccurate. A package may weigh very little but still be charged at a higher “dimensional weight” rate if it is physically large. By understanding and properly configuring dimensional rating in Odoo, you can get more accurate rate estimates and prevent unexpected shipping charges.

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How Dimensional Weight Is Calculated

Carriers use this formula:

Dimensional Weight = (Length × Width × Height) ÷ Divisor

• Divisor – Typically 139 for standard UPS/FedEx accounts (varies by contract; sometimes 160).
• Units – Inches for dimensions, pounds for weight.
• Billing – Carrier charges the greater of actual weight or dimensional weight.

Example:

• Box size: 36” × 24” × 18” = 15,552 cubic inches
• Dimensional weight = 15,552 ÷ 139 ≈ 112 lbs
• Actual weight: 20 lbs → Charged as 112 lbs

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How Odoo Uses Dimensional Rating

• Odoo does not physically simulate packing items into boxes.

• It uses product dimensions and weight to decide:

  • Whether items fit into a defined box
  • How many boxes are needed
  • Which box sizes to use
  • Important: Odoo fills boxes based on the weight limit, not the available volume. If the weight limit is reached, a new box is created even if unused space remains.

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Configuring Odoo for Accurate Rates

To improve rate accuracy:

1. Enter accurate product dimensions – Match how the item is packaged (folded vs assembled).
2. Record correct product weights.
3. Define accurate box dimensions in Shipping Methods.
4. Set realistic max weight limits per box – sometimes these need fine-tuning to match real carrier costs.

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How Rates Are Calculated in Practice

1. Odoo assigns items to boxes.
2. Odoo/EasyPost calculates both the actual and dimensional weights.
3. The integration sends details to the carrier.
4. Carrier charges for whichever weight is higher.

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Summary

Odoo’s dimensional rating is a calculation tool, not a packing engine. The accuracy of your shipping rates depends on:

• Correct product dimensions and weights
• Packaging details matching real-world conditions
• Properly configured box sizes and weight limits

Accurate data in = accurate rates out.