Why Volumetric Weight Matters: The Hidden Cost in Ecommerce Shipping

Are your shipping costs higher than expected? The culprit might be something you've never heard of: volumetric weight.

With ecommerce, understanding shipping calculations has become essential to maintaining healthy profit margins. Yet many businesses overlook one crucial factor that could be silently inflating their shipping costs.

The Tale of Two Weights

When carriers calculate your shipping costs, they don't just consider how heavy your package is—they also look at how much space it takes up. This is where the concepts of dead weight and volumetric weight come into play.

Dead Weight: What Your Scale Tells You

Dead weight (or actual weight) is straightforward—it's simply how much your packaged product weighs on a scale. If you sell heavy items like books or tools, dead weight is likely what determines your shipping costs.

Volumetric Weight: The Space Your Package Occupies

Volumetric weight (also called dimensional or cubic weight) measures the space your package takes up rather than its physical weight. This calculation becomes crucial for lightweight but bulky items.

Why carriers care about space: Think about it from the carrier's perspective—a truck can only hold so many packages, regardless of how light they are. A giant box of pillows might weigh very little but takes up space that could otherwise fit several smaller, potentially more profitable packages.

Carriers that utilise a volumetric weight structure will measure every package against both volumetric and dead weight, and use the larger as the ‘weight’ which is then applied to the rate card.

How Volumetric Weight Is Calculated

The formula varies slightly depending on which measurement system and carrier you use, but the concept remains the same:

If You're Using Inches and Pounds (US System):

(Length × Width × Height in inches) ÷ Divisor = Volumetric Weight in pounds

Common divisors:

• UPS and FedEx: 139 for domestic shipments

• USPS: 166 for domestic shipments

If You're Using Centimeters and Kilograms (Metric System):

(Length × Width × Height in centimeters) ÷ Divisor = Volumetric Weight in kilograms

Common divisors:

• DHL and many international carriers: 5,000

• Some Asian carriers: 6,000

Let's See It in Action:

Example: You're shipping decorative pillows in a box measuring 18" × 18" × 6".

• Actual weight: 2 pounds

• Volumetric calculation: (18 × 18 × 6) ÷ 139 = 13.9 pounds

The result? The carrier charges you for a 13.9-pound package, even though it actually weighs only 2 pounds!

For that example pillow shipment:

• Major carrier using volumetric weight: $21.85 (based on 13.9 lbs)

• Regional carrier using actual weight only: $12.40 (based on 2 lbs)

That's a difference of $9.45 per shipment—money that directly impacts your bottom line.

Smart Strategies for Ecommerce Retailers

1. Optimize Your Packaging

The simplest way to reduce volumetric weight charges is to use appropriately sized packaging:

• Eliminate unnecessary empty space
• Consider compression packaging for soft goods
• Use poly mailers instead of boxes when possible
• Test different box configurations to find the most efficient dimensions

2. Know Your Product Portfolio

Different products may benefit from different shipping approaches:

• Dense, heavy products (jewelry, tools) → Major carriers with established networks
• Light, bulky products (bedding, lampshades) → Consider dead weight-only carriers

3. Implement a Multi-Carrier Strategy

Don't put all your shipping eggs in one basket:

• Use dead weight-only carriers for bulky, lightweight products
• Reserve major carriers for items where actual weight exceeds volumetric weight
• Consider regional carriers for specific delivery zones

4. Discuss with your Provider

If you have consistent shipping volume:

• Ask about special rates for your specific product types
• Consider asking for seasonal adjustments for peak periods

5. Build Shipping Costs into Your Pricing Strategy

Once you understand volumetric weight:

• Factor accurate shipping costs into your product pricing
• Consider charging dimensional weight shipping on categories most affected
• Test free shipping thresholds that account for dimensional weight impacts

Making the Right Trade-Offs

When choosing between carriers that use volumetric weight and those that don't, consider these factors:

The Bottom Line

Understanding volumetric weight isn't just about avoiding surprise costs—it's about strategically optimizing your entire fulfillment operation. By making informed decisions about packaging, carrier selection, and product design, you can significantly reduce shipping expenses while maintaining customer satisfaction.

At Borderless360, we're here to help you navigate these complexities and find the shipping approach that works best for your unique product mix. Contact our team today to learn how we can help you implement these strategies and more.