Open an LTL invoice and you may find a billed weight that is higher than what you actually shipped. Sometimes that is a reweigh. Often it is something else entirely: a weight break working in your favor. Knowing the difference keeps you from disputing a charge that saved you money, and from missing one that did not.
What a weight break is
LTL rates are quoted per hundredweight (per 100 lbs, or CWT). A weight break is a threshold in the carrier's tariff where that per-CWT rate changes, almost always downward as weight goes up. Common tiers are:
- L5C: less than 500 lbs
- 5C: 500 lbs
- 1M: 1,000 lbs
- 2M: 2,000 lbs
- 5M: 5,000 lbs
- 10M: 10,000 lbs
The names and the tiers available vary by tariff. The logic is the same everywhere: dock labor, paperwork, and loading time are largely fixed per shipment, so a heavier shipment spreads those costs across more pounds and earns a lower rate per hundred.
The 480 lb shipment that rates as 500
Because the rate drops at each threshold, a shipment just under a break can cost more than a heavier one just over it. Take a 480 lb shipment and these illustrative rates (not a specific carrier's tariff):
| Rating method | Billed weight | Rate per CWT | Charge |
|---|---|---|---|
| Actual weight | 480 lbs | $42.00 | 4.8 × $42.00 = $201.60 |
| 500 lb weight break | 500 lbs | $28.00 | 5.0 × $28.00 = $140.00 |
The shipment weighs 480 lbs, but rating it as 500 lbs at the next tier produces the lower charge: $140.00 instead of $201.60. Many carrier and TMS rating engines apply the lower charge automatically when the governing weight-break or deficit-weight rule allows it. That is why the invoice shows 500 lbs.
A weight break is not a reweigh
These two look alike on paper and are opposites in practice:
- Weight-break rating is a pricing mechanism. Your actual weight did not change. The carrier simply calculated the charge against the tier that costs you less.
- A reweigh is a correction. The carrier weighed the freight, found it heavier than the bill of lading said, and raised the billed weight and the charge.
When billed weight is higher than declared weight, check which one happened before you react. If it is a reweigh you disagree with, see how to dispute a reweigh or reclass.
The shape of the rate curve
Here is how a typical per-CWT curve falls as weight rises. Again, these figures are illustrative:
| Weight tier | Illustrative rate per CWT |
|---|---|
| L5C (under 500 lbs) | $42.00 |
| 5C (500 lbs) | $28.00 |
| 1M (1,000 lbs) | $19.50 |
| 2M (2,000 lbs) | $14.25 |
| 5M (5,000 lbs) | $9.80 |
The drop is steep. That is the reason consolidation works: combining two small shipments into one heavier shipment can move the freight into a cheaper tier and lower the cost per pound. Actual savings depend on class, lane, minimum charges, accessorials, and the carrier's cubic-capacity or linear-foot rules, so run the numbers before you change how you ship.
Weight and class work together
In a traditional tariff, your rate sits at the intersection of freight class and weight tier for the lane. Optimizing only one leaves money behind. A strong discount on class 100 freight does less for you if your shipments consistently land just under a weight break and never reach the next tier.
How to use weight breaks
- Know your typical weights against the carrier's thresholds. A shipment that is routinely just under a break may be worth consolidating up to just over it.
- Audit billed-weight increases. Confirm each one is the weight-break rule and not a reweigh you never heard about.
- Ask for the full weight-break schedule when you negotiate. A discount often varies by tier. A carrier can offer an attractive headline number while putting the real savings in tiers you rarely ship.
For how weight breaks fit with the base tariff, discount, and fuel, see how LTL rates are calculated.