Why this question is back in 2026
Three years of CPG growth ran on pricing. When pricing slows (Danone's FY 2025 reported shows +1.8% pricing versus +2.7% volume/mix), every commercial director suddenly has the same conversation with the CFO. Volume has to do the work, and pack architecture is the lever.
The math
On a 100g pack at €1.00, a 5% price rise lifts you to €1.05. A 5% pack shrink takes you to 95g at the same €1.00. Per-100g revenue is identical: €10.50 versus €10.53. To finance, the levers look interchangeable.
The consequences are not. Price rise is visible at the shelf and sales-elastic; the typical CPG category elasticity around minus one means a 5% price rise costs roughly 5% of volume. Pack shrink is invisible at first, less elastic, but harder to reverse. Once the 95g pack ships, returning to 100g looks like a price cut.
Three signals to read before choosing
- How tight is the retailer relationship? If your retailers are already pushing back on grammage cuts (Tesco's revised supplier terms in 2025 are an example), pack shrink is more expensive than the math says. And the cost is not just the immediate margin hit. It is the next round, when the same buyer remembers the pack-shrink move and pushes harder on listing fees, slot allocation, or promo participation. Retailers have long memories on grammage, and they price that memory into your trade terms two cycles later.
- How visible is unit price in the category? In categories where unit-price labelling is standard and shoppers actually use it (laundry, pet food, paper), pack shrink lands harder and the second one is significantly more expensive than the first. In categories where the per-pack price is the headline and unit price is in small print (snacks, biscuits, breakfast cereal), pack shrink slides through more easily on the first move, but only the first time.
- How recent was the last move? Pack shrink is reversible but every reversal costs trust. If you shrunk in 2023 and the shopper noticed, the second shrink is significantly more expensive.
The Danone FY 2025 read as a real-time example
Danone's European EDP business reported "sustained momentum" with the volume/mix engine outpacing pricing for the first time since 2022. Read against the three signals above, this is what it looks like when retailer relationships are healthy (signal 1 favourable), unit price is visible but not weaponised (signal 2 mixed), and the brand has been quietly rebuilding pack architecture across the inflation cycle (signal 3 favourable).
The rubric is unchanged: trust as binding constraint goes price rise; retailer as binding constraint with healthy trust goes pack shrink; both binding goes split, two-thirds price plus one-third pack, staged three months apart.
Two failure modes I see most often
The first failure mode is treating the choice as a finance question. Finance people see equivalent per-100g revenue and pick whichever is faster to pass through. Commercial people forget that finance is right about the maths and wrong about what comes after the maths. The shopper trust dynamic, the retailer dynamic, the reversibility dynamic, none of those show up in the spreadsheet. They show up in your share of category eighteen months later. The fix is to bring the commercial team into the room before the finance lever gets named, not after.
The second failure mode is shipping both moves on the same SKU at the same time. A 5% price rise on a 100g pack is one signal to the shopper and the buyer. A 5% pack shrink to 95g is a second signal. Doing both at once is three or four signals, and the second one is the reversal trap: the buyer logs the price rise, sees the pack shrink, and concludes you are running a margin grab rather than a category move. Stage them. Three months apart at minimum, six is better. The paper trail matters more than the cycle calendar.
What changes in 2026 vs 2024
The retailer side has hardened. Most major European grocers tightened position on grammage cuts through 2025. The default for 2026 is shifting back toward price rise as the cleaner first move, with pack shrink reserved for situations where retailers explicitly accept it.