Gross Combination Weight Check
Whether a tractor-trailer is within its weight limits.
Example
You enter
- Rated GCWR (lb) 80000
- Power-unit weight, loaded (lb) 18000
- Trailer weight, loaded (lb) 60000
- Federal gross cap (lb) 80000
You get
- Combined weight 78000 lb
- GCWR margin 2000 lb
- Federal margin 2000 lb
- Within both limits Yes
Details, formula, and sources
The combined power-unit plus trailer weight checked against both the manufacturer's rated GCWR and the federal 80,000 lb gross cap (editable), reporting each margin and the binding limit. Axle and bridge-formula limits are separate checks; a permit or the AHJ governs an over-limit move.
combined = tractor + trailer; the binding limit is min(GCWR, federal_max); ok if combined <= binding, else over by combined - binding. GCWR margin and federal margin are reported separately.
23 CFR 658.17 (80,000 lb federal gross) and 49 CFR 393.75 by section, with the manufacturer's GCWR rating plate; limits not reproduced.
Read-only at ecfr.gov. State limits may be lower than federal; a permit or the AHJ governs an over-limit move.
Math aid for personal verification. The ELD on the truck and the carrier tariff are the legal record. State limits may be lower than federal.
Field names used by the API: gcwr_lb, tractor_weight_lb, trailer_weight_lb, federal_max_lb, combined_lb, margin_gcwr, margin_fed, ok
- Binding limit the smaller of the rated GCWR (structural / drivetrain) and the federal gross cap governs23 CFR 658.17
- Federal cap editable default 80,000 lb; edit for a state or permit limit23 CFR 658.17
- Separate checks axle limits and the federal bridge formula are separate checks, not covered here23 CFR 658.17