Your real towing capacity
The formula
capacity = GCWR − (curb weight + passengers + cargo)
Worked example
A 12,000 lb GCWR with a 5,550 lb loaded vehicle leaves 6,450 lb.
Assumptions
GVWR and GCWR are defined at 49 CFR § 571.3. Towing capacity is GCWR minus the fully loaded tow vehicle — not a standalone number off a brochure. Passengers, fuel, cargo and the hitch itself all come off before anything is attached.
Reference table
| GCWR | Loaded vehicle | Available |
|---|---|---|
| 12,000 | 5,550 | 6,450 |
| 14,000 | 6,200 | 7,800 |
| 16,000 | 7,000 | 9,000 |
| 20,000 | 8,500 | 11,500 |
Sources (2)
- Electronic Code of Federal Regulations — 49 CFR § 571.3 — Definitions (GVWR, GCWR) (accessed 2026-08-17) T1
- SAE International — J2807 — Performance Requirements for Determining Tow-Vehicle Gross Combination Weight Rating (accessed 2026-08-17) T2