GCWR calculator: combined truck and trailer weight
GCWR (gross combined weight rating) is the most your loaded truck and loaded trailer may weigh together. Add curb weight, people, cargo, the hitch and the trailer, and keep the total at or under GCWR. The heaviest trailer your GCWR allows is GCWR minus the loaded truck.
Combined weight check
Add it to see which limit is lower.
Combined 14,630 of 15,000 lb (370 lb left)
- Within · Combined 14,630 of 15,000 lb
- GCWR allows a trailer up to 8,870 lb.
Show the math
Combined weight = curb + people + cargo + hitch hardware + trailer weight.
GCWR left = GCWR − combined weight.
Heaviest trailer by GCWR = GCWR − (curb + people + cargo + hitch hardware).
How to use
- Find GCWR in your owner’s manual or the maker’s towing guide for your exact configuration.
- Enter curb weight, or weigh the truck at a scale with a full tank.
- Add the people, cargo and hitch hardware.
- Enter the loaded trailer weight.
- Add your trailer rating to see which limit is lower.
The formula
- Combined weight = curb weight + people + cargo + hitch hardware + trailer weight
- GCWR left = GCWR − combined weight
- Heaviest trailer by GCWR = GCWR − (curb + people + cargo + hitch hardware)
Example 1
A half-ton with a 15,000 lb GCWR and a 5,400 lb curb weight carries two adults (360 lb), 300 lb of gear and a 70 lb hitch. With an 8,500 lb trailer the combination weighs 14,630 lb, 370 lb under GCWR. GCWR alone would allow a trailer up to 8,870 lb.
Example 2
Same truck, four adults (680 lb), 400 lb of gear and a 9,300 lb trailer: 15,850 lb, 850 lb over GCWR. The trailer is within a 9,300 lb tow rating, yet the combination is over. Both limits apply at once.
What this calculator doesn't cover
GCWR is only one limit. It doesn’t check payload, tongue weight, axle ratings or the hitch. Makers set GCWR for sea-level conditions; Ford, for example, reduces gross combined weight by 2% per 1,000 ft of elevation. Use the towing capacity calculator to check everything together.
Reference table: GCWR examples from 2026 guides
| Truck (2026) | Configuration | GCWR (lb) | Max trailer (lb) | Source |
|---|---|---|---|---|
| Chevrolet Silverado 1500 | 5.3L V8, Crew Cab Short Box 4x4 | 15,000 | 9,300 | Chevrolet, 2026 Trailering Guide |
| Chevrolet Silverado 1500 | 3.0L Duramax, Max Trailering Pkg, 20" wheels, Double Cab Std Box 2WD | 19,000 | 13,300 | Chevrolet, 2026 Trailering Guide |
| Ford F-150 | 3.5L EcoBoost, 3.55 axle, Tow/Haul Pkg + Max Tow Axle | 19,400 | 13,500 | Ford, 2026 RV & Trailer Towing Guide |
| Ram 1500 | 3.0L Hurricane SO, 3.92 axle | 17,000 | 11,610 | Ram, 2026 Ram 1500 Payload & Towing chart |
Tips
- GCWR is set for the exact engine, axle ratio and tow package. Two trucks that look the same can have different GCWRs.
- Weigh the whole rig at a CAT scale. The ticket shows steer axle, drive axle and trailer axles separately.
- Elevation matters. Plan for less margin if you tow through the mountains.
FAQ
How do I figure out the GCWR of my truck?
Look in your owner’s manual or the manufacturer’s towing guide for your model year, then find the row that matches your engine, cab, bed, drive and axle ratio. Ford, Chevrolet and Ram publish GCWR in their towing guides. The door-jamb sticker shows GVWR and axle ratings, not GCWR.
What is my GCWR by VIN?
The VIN tells you the exact engine and trim, which you need to pick the right GCWR row. Ford’s online towing calculator looks it up from the VIN for F-Series trucks. The free NHTSA VIN decoder may show a GCWR range for some vehicles, but often leaves it blank.
Is GCWR the same as towing capacity?
No. Towing capacity is the heaviest trailer the truck can pull with only a driver and passenger aboard. GCWR is the limit for truck plus trailer together. GM calculates the trailer rating as GCWR minus curb weight minus 300 lb for the driver and passenger, so every pound you add to the truck lowers what you can tow.
What happens if you exceed GCWR?
The engine, transmission, cooling system and brakes are working past what the maker tested for. You’ll see slower climbs, hotter transmission temperatures and longer stopping distances. It can also void warranty coverage for related damage and affect insurance after a crash.
Does GCWR include passengers?
Yes. GCWR covers everything: the truck, its fuel, every person, cargo, the hitch and the loaded trailer. That’s why a full cab can push a combination over GCWR even when the trailer is under the tow rating.
Related tools and pages
Sources
- Chevrolet, 2026 Trailering Guide · read 2026-10-19
- Ford, 2026 RV & Trailer Towing Guide · read 2026-10-20
- Ram, 2026 Ram 1500 Payload & Towing chart · read 2026-10-19
- Truck Parts & Service, SAE J2807 overview · read 2026-10-19
Written by Sikander Mushtaq. I build HitchMath's calculators and check every towing number against the manufacturer's own guide or spec page. Read how we calculate.
Last updated: 2026-10-19 · Editorial policy
HitchMath figures come from manufacturer documents and are for planning only. Your truck's door-jamb sticker, owner's manual and a scale ticket are the final word.