CWT Weight-Break & Bump Optimizer
Real LTL tariffs don’t use one rate — the rate per CWT drops as the shipment gets heavier. Enter your weight breaks and this rate-shops all of them, including shipping at a higher bump (deficit) weight to catch a lower rate, and reports the cheapest legal bill. Pounds or kilograms.
Total billable weight of the shipment.
The tariff’s absolute minimum charge (AMC), if any.
Weight breaks
Rate per CWT at each break, lightest first
Cheapest freight cost
| Rating | Rated weight | Rate / CWT | Charge |
|---|
Weight breaks and the “lower of” rule
An LTL tariff quotes a rate per CWT (per 100 lb) that steps down as the shipment crosses weight thresholds — the weight breaks. A shipment’s charge is normally its weight in hundredweight times the rate for its break. But carriers are bound by a “lower of” rule: they must bill the lower of the actual-weight charge and the charge computed at any higher break’s minimum weight using that break’s lower rate. This tool checks every break and returns whichever is cheapest.
Bump (deficit) weight
When rating a shipment as the next break’s minimum weight beats its actual-weight charge, that extra weight is the bump or deficit weight. It looks backwards — you’re paying for weight you don’t have — but the lower rate more than makes up for it.
The bump is the freight world’s clearest free lunch: declare more weight, pay less. It only appears when the next break’s rate is low enough, which is exactly what this tool checks for you.
A worked example
A 1,900 lb shipment on a tariff with 1,000 lb @ $30/CWT and 2,000 lb @ $25/CWT: at its own break it’s 19 × $30 = $570. Bumped to 2,000 lb it’s 20 × $25 = $500. The bump wins — you rate the shipment as 2,000 lb (a 100 lb deficit) and bill $500, saving $70, an effective $26.32 per CWT on your real weight.
What this doesn’t do
This optimizes across the breaks you enter — it isn’t a rating engine and doesn’t look up your carrier’s tariff, apply FAK or discounts, add fuel surcharge, or account for accessorials. Confirm the billable weight the carrier will rate first, enter the breaks from your rate agreement, and treat the result as the linehaul before surcharges.