Lara Guevara shows how oversized packaging inflates 3PL bills by 30-50% through dimensional weight billing (L × W × H ÷ 139), turning a 2-lb product into a 7-lb charge. The real problem: marketing, finance, and merchandising choose box size without seeing freight impact. She outlines three fixes: audit top SKUs, document an escalation process with your 3PL, and record negotiated storage terms in an operations playbook.
Chapters
Two weeks down, the three PL relationship test, the storage surcharge loss. Today, I'm teaching a third fix. I'm Lara. This is Move Supply Chain, and let's start with the new one because most founders have genuinely never run this math on their own product. Carriers bill dimensional weight, not just actual weight. The formula is length times width times height divided by 139, whichever is higher. Your product's real weight or that calculation is what you pay for. Work example: Your product weighs. 2 pounds. It ships in a box 12 by 10 by 8, a completely ordinary size. 12 times 10 times 8 is 960 divided by 139 is just under 7. So a 2-pound product billed as though it weighs almost 7. That's not a rounding error. It's more than 3 times the real weight on every single shipment you make. At volume, that's serious money, often 30 to 50% more than it needs to be on a best-selling SKU, and it never appears as a one-line item you could question. It's just baked into a freight bill that looks like shipping got more expensive, which is a sentence every founder has said at some point without investigating further. Go and run this on your top sellers box dimension. It takes 90 seconds, and most people who do it for the first time find a real gap. Now here's the part I find genuinely fascinating about beam weight and the reason it belongs in an alignment month rather than a logistics month. Think about who actually chose your box. In most brands' resides, the box was chosen by whoever was designing the unboxing experience. Someone on the brand or marketing side working on how it feels to open, whether the product sits nicely, whether there's room for tissue in a cart, reasonable and genuinely valuable unboxing matters. And that person has almost certainly never seen a packing voice. So you have a decision made for brand reasons. Billed to operations, absorbed by finance, and nobody in that chain has ever sat in a room together about it. That's not incompetence. It's just that nobody's job description says reconcile the aesthetics of the box against the freight cost of the box. So the trade-off never gets made explicitly. It gets made by default by whoever moves first. Now let me trace that. What an inch actually touches. Brand and creative. An inch of extra void space is a nicer unboxing and a real freight cost. That's a legitimate trade-off, and it might genuinely be worth paying. What's not legitimate is not knowing you're making it. Once you can put a number on the inch, the conversation becomes a decision instead of an accident. Marketing. And this is the connection I'd most like you to take away. Your free shipping threshold and your box dimensions are secretly the same decision. If you offer free shipping over some amount, you are absorbing the freight cost, which means you are absorbing the ding weight penalty on every one of these orders. So an oversized box doesn't just cost you shipping, it quietly moves the point at which free shipping stops being profitable, and almost no brand recalculates the threshold when packaging changes. You changed the box in March and your free shipping threshold has been wrong since March. Merchandising and bundling. Bundles are usually designed around what customers want together, which is great, but 2 products that pack into one existing box and 2 that force a bigger box have meaningful different economics, and that almost never enters the bundle design conversation. Same revenue, different margin, and the difference is a cardboard decision. Finance. Freight per order is a contribution margin input, so a packaging change is a margin change that shows up nowhere in your TPL as a packaging lie. It surfaces as freight creeping up and everyone blaming the carrier. And you're TPL from week 1 because pick and pack rates and storage both key off carton size too. A smaller carton is cheaper to ship, cheaper to store, and often cheaper to handle. The same inch pays you back 3 times. So one dimension on one box and it reaches brand marketing's threshold math. Bundle design, contribution margin, and your warehouse bill. This is the thing I'd want you to take from the whole of September. Honestly, every one of the 3 weeks looked like a logistics topic and none of them were actually work. The 3PL relationship was a customer experience decision. The storage clause was a merchandising decision. The box is a marketing decision. Supply chain is where the bill arrives. It's very rarely where the decision was made. Now, which brings us today and why I put all 3 of this in one month on purpose. 3 fixes, each genuinely useful on its own. And here's what happens to most founders anyway. You fix the thing you just learned about, you move on, and 6 months later you cannot remember what you negotiated or whether it's still being honored. 3 good fixes sitting in 3 different places, none of it documented anywhere a person on your team could pick up and follow. It isn't new information at this point, it's a format. A documented escalation process, the name, direct line, the backup contact to your 3PL during peak, written somewhere your team can find at 6 PM on a Friday in November. Your negotiated storage terms, the actual cap, The notice period, the effective date. Save us a real reference instead of half-remembered call and a dim weight audit of your top SKUs using the formula so packaging decisions get made against real numbers going forward. That's what built rather than winged actually means. Not smarter fixes written down in one place that outlive the week you learned about them. Owner's test on all 3 at once and be honest with yourselves. What are they called? Who runs each one when you're not in the room? When do they recur and whose calendar? Where are they written? My honest expectation is most of you can describe all 3 fixes fluently right now and none of them are written anywhere. That's not a character flaw, it's the default state of every growing business. And the gap between describing a fix, having a system, is where basically All founder exhaustion leaves, you keep resolving. If you're joining live, the operations playbook is linked below and it's a strong thing to build from on your own. But build that, don't just watch this and agree with it. Because agreeing with me costs you nothing and changes nothing. That closes September. Next month, we shift from the systems you control to a part of your supply chain a lot of you thought you'd already handled by moving production somewhere else.
