Dimensional weight helps price bulky but lightweight packages more accurately by considering package volume.

How it works

When dimensional weight is enabled, the plugin calculates a DIM weight from product dimensions and a DIM factor, then uses the greater of actual weight and dimensional weight in surcharge calculations.

dim_weight = (length × width × height) / DIM_factor
effective_weight = max(actual_weight, dim_weight)

Use Dimensional Weight

• Purpose: Turns dimensional weight on for weight-based surcharges.
• Options: On or Off.
• Recommended: On when shipping bulky lightweight goods. Off when all products are dense and actual weight already reflects shipping cost.

DIM Factor

• Purpose: Divisor that converts package volume to a weight value.
• Options: Any positive number. Typical carrier values: 5000 for metric (cm/kg) and 139 for imperial (in/lb).
• Recommended: Use the value your carrier publishes. UPS, FedEx, and DHL publish current DIM factors per service.
• Example: A 60 × 40 × 30 cm box at DIM 5000 has dim weight of (60 × 40 × 30) / 5000 = 14.4 kg. If the actual weight is 8 kg, the effective weight used for surcharges is 14.4 kg.

When to use it

• Furniture, frames, signs, packaging, or other bulky goods.
• Products where carrier charges are based on volume.
• Stores where actual product weight underestimates shipping cost.

Use the same unit system and DIM factor your carrier expects, then test sample products before enabling it broadly.

Related

See Weight-Based Surcharges for the surcharge calculation that consumes the effective weight, and Developer Reference for the carticy_dimensional_weight filter to override the computed value.