Volumetric Weight Explained: How Carriers Calculate Shipping Costs

Volumetric Weight Explained

Ever been surprised by a shipping quote for a light but bulky package? That's because carriers don't just charge by actual weight — they also consider the space your package takes up. This is called volumetric weight (also known as dimensional weight or DIM weight).

How Volumetric Weight Is Calculated

The formula is simple:

Volumetric Weight = (Length x Width x Height) / DIM Factor

Measurements are typically in centimeters, and the result is in kilograms. The DIM factor varies by carrier:

• DHL Express: 5,000
• FedEx: 5,000
• UPS: 5,000
• Postal services: 6,000 (usually more generous)

For example, a box that is 40cm x 30cm x 20cm: - Volumetric weight = (40 x 30 x 20) / 5,000 = 4.8 kg - If the actual weight is only 1 kg, you'll be charged for 4.8 kg

Why Carriers Use Volumetric Weight

Cargo space in aircraft and trucks is limited. A large, light box takes up the same space as a large, heavy box. Volumetric weight ensures carriers are compensated for the space your package occupies, not just its weight.

How to Reduce Volumetric Weight

• Use the smallest box possible. Don't put a small item in a large box with excess padding.
• Consider flexible packaging. Poly mailers and padded envelopes have no volumetric weight penalty for most carriers.
• Repack if needed. If the seller shipped your item in an oversized box, repack it before forwarding.
• Remove unnecessary packaging. Extra boxes-within-boxes inflate your volumetric weight.

Which Weight Does the Carrier Use?

Carriers compare the actual weight and volumetric weight, then charge based on whichever is higher. This is called the "billable weight" or "chargeable weight."

Impact on Shipping Costs

Volumetric weight can dramatically increase costs. Consider this example:

• A box of pillows: actual weight 2 kg, volumetric weight 12 kg
• You'd be charged for 12 kg — potentially 6x more than expected

Check Your Rates on RateShips

When comparing shipping rates on RateShips, enter your package dimensions along with the weight. RateShips calculates the volumetric weight automatically and shows you the billable weight each carrier will charge. This helps you avoid surprises and choose the most cost-effective option.

Key Takeaways

• Volumetric weight = L x W x H / DIM factor
• Carriers charge the higher of actual vs. volumetric weight
• Use smaller packaging to reduce costs
• Always check volumetric weight before shipping bulky items