Methodology · revision 4
Here is the arithmetic. Disagree with it specifically.
- Revision
- 4 — August 2026
- Basis
- Per box, per reuse cycle
- Stance
- Mid-range, not best case
Challenge a number
If you have better mill-specific data, send it. We have revised this page three times because customers argued with it.
1 · What we are comparing
Every figure is a counterfactual: what would have happened if the reuse had not. The baseline assumes the customer buys an equivalent new box, manufactured from a mid-range mix of virgin and recovered fibre, and that the existing box is discarded at end of its single use. That is what happened at most of our customers before they called us — but it is an assumption, and we label it as one in every statement we issue.
2 · Board weight per box
Savings scale with the pounds of containerboard that did not have to be produced, so the weight of the box matters more than its dimensions. These are the weights we use, measured on our own scale across incoming lots rather than taken from a supplier catalogue.
| Box class | Board weight | Basis | Sample |
|---|---|---|---|
| 4-wall 48 × 40 × 36 | 18 lb | Weighed flat, no liner or lid | 412 boxes |
| 5-wall 48 × 40 × 36 | 24 lb | Weighed flat, no liner or lid | 587 boxes |
| 5-wall 48 × 40 × 48 | 29 lb | Weighed flat, no liner or lid | 126 boxes |
| Octabin 44″ round × 36 | 21 lb | Body only, excludes cap and base | 203 boxes |
| Used shipping carton, double wall | 1.6 lb | Averaged across mixed sizes | 1,900+ cartons |
3 · The six factors
| Factor | Value used | Applied to | Why this value |
|---|---|---|---|
| Carbon intensity of avoided board | 0.95 lb CO₂e / lb | Board weight × reuse cycles | Mid-range cradle-to-gate containerboard figure for North American production on a mixed virgin and recovered furnish. |
| Process water avoided | 2.7 gal / lb | Board weight × reuse cycles | Pulping, forming and drying water, net of mill recirculation. Conservative against older published figures. |
| Trees per ton of virgin fibre | 17 trees / ton | Virgin-share of avoided board | The long-standing industry conversion for uncoated paper; we apply it only to the virgin share of the furnish. |
| Landfill mass avoided | 1 lb / lb | Board weight × reuse cycles | Direct. A pound of board reused is a pound not entering a compactor at end of that cycle. |
| Freight penalty | Subtracted | Lane distance × load share | Diesel burn for collection and delivery, reduced by the share of moves matched to existing backhauls (currently 38% of our miles). |
| Cost delta | $8 – $13 / box | New price minus used price | Observed spread on five-wall 48 × 40 × 36 over the trailing twelve months, before freight. |
4 · Worked example
A plastics compounder moves 400 five-wall 48 × 40 × 36 boxes per month and our stock averages 3 further trips per box before it is retired.
- 400 × 12 = 4,800 boxes a year
- 4,800 × 3 = 14,400 reuse events
- 14,400 × 24 lb = 345,600 lb of containerboard not manufactured
- × 0.95 = 328,320 lb CO₂e ≈ 164 tons avoided
- × 2.7 = 933,120 gallons of process water not drawn
- (345,600 ÷ 2,000) × 17 = ≈ 2,938 trees on a fully virgin counterfactual
- 345,600 lb = ≈ 173 tons not landfilled
- 14,400 × $11.50 ≈ $165,600 of packaging spend avoided
The freight penalty for that customer — a 210-mile lane with 41% backhaul matching — comes to approximately 11 tons of CO₂e over the year, which we subtract, giving a net of about 153 tons. That netting is why our published figures are lower than several competitors quoting the same volumes.
5 · Where this is conservative
- We ignore avoided end-of-life emissions. Landfilled corrugated generates methane as it decomposes. Counting it would increase our figures materially; we leave it out because the rate varies enormously by site.
- We ignore fibre-length value. Every pulping cycle shortens fibre and eventually forces virgin input into the system. Reuse defers that permanently, and no common factor set captures it.
- We count only the box. Liners, caps, pallets and stretch wrap that also get reused are excluded from headline numbers unless a customer asks for a full-shipment model.
6 · Revision history
- Rev 1, 2021 — first published factor set, single carbon figure, no freight penalty.
- Rev 2, 2023 — freight penalty introduced after an internal review found our claims unqualified.
- Rev 3, 2025 — board weights replaced with our own weighbridge and scale data.
- Rev 4, 2026 — water factor reduced to 2.7 gal/lb; trees applied to virgin share only.
Use it
Take the factors and run your own model.
The numbers above are not proprietary. If your sustainability team wants to apply them to volumes you buy elsewhere, that is a perfectly good outcome for us.
Using it
How to apply this factor set to your own volumes.
Six steps, about twenty minutes, and the result is defensible in an audit because every input is published.
- 01
Count containers, not tonnes
Units by footprint and wall construction. Tonnage is a recycling metric and it will systematically understate reuse.
- 02
Apply our measured board weights
18 lb for a 4-wall 48 × 40 × 36, 24 lb for a 5-wall, 29 lb for a tall 5-wall, 21 lb for an octabin body. Weighed here, not taken from a catalogue.
- 03
Multiply by further trips, not total trips
The counterfactual is the box you did not buy. If your stock averages three further trips, that is three avoided manufactures per container.
- 04
Apply the factors
0.95 lb CO₂e and 2.7 gal of process water per pound of avoided containerboard; 17 trees per ton on the virgin share only.
- 05
Subtract freight
Lane distance and matched backhaul share. Skipping this is the most common way published reuse claims become indefensible.
- 06
State the counterfactual in writing
What would have happened without the reuse. For most operations that is buying new and discarding the old; for some it is not, and saying so is what makes the rest credible.
Scrutiny
Questions an auditor should ask us.
Published because a factor set that cannot survive these questions is marketing, and we would rather be asked them than not.
- What is the counterfactual, stated explicitly?
- Where do the board weights come from, and how many were measured?
- Is freight netted off, and on what basis?
- What is excluded, and would including it help or hurt the figures?
- When was the factor set last revised, and did the revision raise or lower the claims?
- Do the unit counts tie to bills of lading and weighbridge tickets?
- How long are the underlying records retained?
- Has any customer's assurance provider tested this, and what did they find?
Want this applied to your actual volumes?
Send counts, sizes and lanes. We will return the modelled diversion and the assumptions we used, in writing.