How much air is your carton mix costing you?

Most warehouses ship air — and pay for it twice: in material and in freight. Here is how to work it out.

Air has a price — three times over

Every centimetre of empty space in a carton costs you in three places: too much corrugated board (material), too much volume on the truck (freight, often billed by volumetric weight) and too much packaging material in the PPWR ratio. The tricky part: none of these costs appears on a single invoice. They are spread out — which is exactly why they go unnoticed.

The calculation: material Δ per carton

Take a carton that is filled to 60% of its volume on average. The remaining 40% is air — but the board for the full carton size is still folded, taped and paid for.

In concrete terms: a medium shipping carton has roughly 0.4 m² of corrugated board surface. At 350 g/m² (common C-flute), that is around 140 g of material per carton. One size smaller and filled to 85% instead of 60%, you save roughly 25–30 g of board — per shipment. At 500 shipments a day, that is a good 13–15 kg of board daily that you would otherwise fold, store, pay for and dispose of. (Example calculation; the real values come from your dimensions and order data.)

This is the material Δ: the difference between the carton you use and the one that would just fit.

More carton sizes are not the solution

The reflex is to widen the range. But every additional size costs storage space, purchasing effort and complexity at the packing station. The question is not “more sizes” but “the right sizes”: Which cartons carry the bulk of your shipments? Which are long tail — rarely used, yet tying up range? Which can you retire without replacement because a neighbouring size covers their job? Three ratings are enough: keep · review · retire.

The double lever: freight and PPWR

Less volume means lower costs twice over. First, freight: many carriers bill by volumetric weight — you pay for the space, not the weight. Second, PPWR: less packaging material per shipment directly improves your ratios and reports. The same optimization pays off on both.

How xl0g calculates this

xl0g compares your carton inventory with your real orders — not with assumptions. Per carton: volume utilization, material Δ in grams and a clear recommendation (keep/review/retire). The method is shown alongside — marked as an estimate until xl0g has recalculated your order data with the packing calculation.

The first step

You do not have to change anything to see it. Have your carton inventory calculated once against a month of real orders — the material Δ list tells you to the gram where the air is.

xl0g — Logistics without gaps. Knowledge over guesswork.