Dimensional Weight (DIM): The Silent Profit Killer in LTL Shipping

Most LTL shippers know the frustration of a freight bill that doesn’t match the original quote. You planned based on scale weight, but when the invoice arrives, the carrier recalculates using something called dimensional weight (DIM). Suddenly, the shipment costs more than expected, and your carefully planned budget is out of balance.

DIM charges are one of the most common and costly pain points in LTL shipping. They’re not always obvious upfront, but they show up later as re-bills, strained carrier relationships, and shrinking profit margins.

Let’s break down what DIM really is, why it quietly eats into your shipping costs, and how you can stop it from draining your bottom line. 

"Carriers don’t just sell space based on pounds, they sell space based on capacity. DIM weight is a calculation that blends actual weight with the amount of room freight takes up inside a trailer". 

That means if you’re shipping something bulky but light, think plastic containers, foam, or furniture, you may be billed as if it weighs far more. A pallet that tips the scale at 500 pounds but takes the same cubic space as a 1,000-pound load will likely be billed closer to the higher number. 

These charges don’t just hit margins; they also create friction. Disputes with carriers slow down billing cycles and tie up internal teams in back-and-forth conversations. Meanwhile, freight held for inspection or reclassification risks missing connections, causing late deliveries and unhappy customers.

And because DIM audits are now standard practice in LTL, avoiding them isn’t possible. If dimensions aren’t accurate, it’s not a question of if the mistake will be caught, it’s only a matter of when.

So, what can we do about it?

One of the biggest drivers of DIM issues is packaging. The way a shipment is wrapped, palletized, and stacked directly impacts density. A few inches of overhang, uneven shrink wrap, or a non-stackable load can reduce stowability, drop density, and push freight into a higher class.

Carriers are using technology to scan freight with precision, which means “close enough” is no longer an option. Guessing or rounding up dimensions is risky; it’s also expensive.

At WTS, we don’t treat DIM as a footnote; we treat it as a critical part of cost management. We work closely with clients to optimize packaging and pallet configurations, ensuring space is used efficiently and density remains favorable.

Want to stop DIM charges from eating into your margins? Visit shipwts.com to learn how we can help.