You can measure now, but cannot yet claim a percentage
What you can and cannot say today
The PPWR (Packaging and Packaging Waste Regulation) entered into force on 11 February 2025 and has applied in large part since 12 August 2026; other obligations are being phased in. The reduction of unnecessary empty space is among the elements still being developed: the precise measurement method has not yet been established.
I therefore do not state a threshold percentage here. Doing so would imply a level of precision that does not currently exist and risks revising an entire range against a standard that may ultimately look different. What you can do is measure using your own data, which will remain useful regardless of the final method.
The practical measure is the fill rate: product volume divided by the internal volume of the box. Two errors are common. First, calculations use external dimensions; with double-wall board, the difference between internal and external dimensions can exceed one centimetre in each direction, compounding the error. The technical FAQ explains this. Second, essential protective space is counted as air. It is not: space required to prevent damage performs a function.
Where oversizing comes from
Rarely a decision, usually a legacy
Almost no one deliberately selects an oversized box. Oversizing arises in four ways, and it helps to identify which applies to you:
- Range simplification. Three sizes were once reduced to one, and the retained size was the largest of the three.
- Volume pricing. The larger size had a lower unit price at a higher order quantity, and the calculation stopped at the box price.
- Product changes. The product became smaller, but the box did not.
- Risk avoidance. Damage occurred in the past, a larger size was selected, and no one subsequently measured whether it remained necessary.
The last is the most difficult because it reflects a genuine trade-off. Preventing damage is a legitimate reason for space, but that space should be substantiated as protective space rather than remaining unexplained clearance. The corrugated board and the PPWR page explains how to record that substantiation.
Reviewing your box range
Four steps using your own order data
The analysis with the greatest potential takes an afternoon and requires no new software: an export of your order lines and a list of your box sizes.
Link order lines to box sizes. How often was each size used during the past year? The distribution is almost always steep: a handful of sizes accounts for most uses.
Calculate the fill rate for each size. Divide product volume by internal volume and weight the result by usage. This identifies not only the poorest fit, but also which poor fit occurs most often.
Find the gaps. Where is there a large jump between consecutive sizes? That is where products are consistently packed too loosely and where an intermediate size can deliver value.
Remove dead sizes. Sizes accounting for less than one per cent of order lines consume stock, space and create error risk without solving a meaningful need.
The trade-off is not simply “fewer sizes or more sizes”. Fewer sizes mean simpler purchasing, lower stock and less risk of picking the wrong box. More sizes mean less empty space and void fill, but also more changeovers and greater operational complexity. The answer depends on your order mix, which is precisely why the analysis must use your own data rather than a rule of thumb.
Calculate the benefits through to the vehicle
That is where the largest figure lies
A saving in board is visible on the purchasing invoice and therefore easiest to demonstrate, but it is usually the smallest item. The effects continue along the chain: a closer-fitting box requires less void fill, more boxes fit per layer and per pallet, less film is needed per shipped unit, and fewer loading metres are used in the vehicle.
The final step is decisive because transport is generally charged by volume rather than weight. A box that is 15% smaller is rarely 15% cheaper in board, but it may make the difference between two journeys and three. Always calculate through to pallets per shipment and loading metres per journey, even if the result remains an estimate.
For the effect on film, the stretch film and the PPWR page explains how to establish film consumption per pallet. The void fill and protective material page covers how much void fill a closer-fitting box can eliminate.
Frequently asked questions about empty space
Concise, practical answers in plain English
The PPWR restricts unnecessary empty space, but the measurement method is still being developed at European level. I therefore do not state a threshold percentage, as that would suggest a level of precision that does not yet exist. You can already measure and improve using your own data, which is also what any future assessment will require.
Divide the product volume by the internal volume of the box. Do this for each box size and weight the result by how often that size is used. Use internal rather than external dimensions, and remember that essential protective space is not empty space.
Both, and that is precisely the trade-off. Fewer sizes mean simpler purchasing, less stock and a lower risk of errors, but also a poorer fit and more void fill. More sizes mean less empty space but greater complexity. The answer depends on your order mix, not on a general rule.
Less board and void fill per shipment, more boxes per pallet, less film per pallet and fewer loading metres. The last two are usually the largest items because transport is charged by volume rather than weight.
Sources and scope
Basis for this guidance
- EUR-Lex — Regulation (EU) 2025/40 — the Regulation itself. Opens in a new window.
- Netherlands Enterprise Agency (RVO) — EU legislation: packaging requirements (PPWR) — Dutch government information. Opens in a new window.
- Verpact — All about the PPWR — timeline and implementation in the Netherlands. Opens in a new window.
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