Empty space inside shipping boxes is more than a minor annoyance — it is a systemic cost drain that quietly erodes profitability across the entire ecommerce supply chain. From inflated shipping fees to higher damage rates and increased material waste, the empty space economy costs the industry billions annually. Understanding where these costs originate is the first step toward eliminating them.
The Hidden Cost of Air
Dimensional weight (DIM weight) pricing, now standard across all major carriers, means you pay for the size of the box — not just its actual weight. When a box is 40% larger than the product inside, you are effectively paying to ship air. For a brand shipping 10,000 orders per month with an average 30% void space, the overspend on DIM weight alone can exceed $15,000 monthly.
But DIM weight is only the beginning. Excess void space requires void fill — paper, air pillows, foam peanuts, or crinkle paper — to prevent product movement and damage during transit. This adds material cost ($0.10-0.50 per package), labor time (stuffing and arranging fill), and waste at the customer's end.
Why Does the Problem Persist?
Most brands default to a small set of standard box sizes — typically 4 to 6 — because managing more sizes adds complexity to the packing process. The result is a compromise: every product gets shoehorned into the closest available box, which is almost always too large. Seasonal product assortments, multi-item orders, and promotional bundles make the mismatch even worse.
The operational inertia is real. Switching box sizes mid-fulfillment slows packing lines. Training staff on new formats takes time. And purchasing small quantities of many box sizes often costs more per unit than buying large runs of a few sizes. These barriers are real — but the cost of inaction is higher.
Right-Sizing Strategies
The most effective approach is right-sizing: matching box dimensions precisely to product dimensions for every order. This can be achieved through three methods:
- Expanded box menu: Increasing your standard box selection from 5 sizes to 12-15 sizes covers the vast majority of orders with minimal void space. The upfront complexity is manageable and the DIM weight savings are immediate.
- On-demand box making: Machines from manufacturers like Packsize and Sparck Technologies create a custom-sized box for every order in real time. The capital investment is significant ($50,000-200,000+) but the ROI is typically under 12 months for high-volume operations.
- Algorithmic box selection: Software analyzes each order's product dimensions and recommends the optimal box from your available inventory. This requires accurate product dimension data but delivers 15-25% void reduction with zero capital expenditure.
Measuring Your Empty Space
To quantify the opportunity, audit 100 recent shipments. Measure the product volume versus the internal box volume for each. Calculate the void percentage. If your average void exceeds 25%, right-sizing will deliver meaningful savings. If it exceeds 40%, it should be a top operational priority.
Track these metrics monthly: average void percentage, DIM weight charges as a percentage of total shipping cost, void fill material spend, and damage rate. As you implement right-sizing, these metrics will improve in tandem — confirming the ROI of every change.
The Bigger Picture
Eliminating empty space is one of the rare supply chain optimizations that improves cost, sustainability, and customer experience simultaneously. Customers prefer receiving right-sized packages (less waste to deal with), carriers prefer denser shipments (more efficient truck utilization), and your finance team will appreciate the savings. The empty space economy is an industry problem — but it is one you can solve at the individual brand level, starting today.
