Towing Calculators
Towing capacity.
Enter your truck's GCWR and curb weight, add what rides in the cab and bed, and get the heaviest trailer you can legitimately tow, limited by the smaller of the GCWR and the tow rating. Runs in your browser; nothing is sent or stored.
Inputs
Result
Fill the form and press Calculate.
Maximum trailer weight = GCWR - loaded tow vehicle weight, and never more than the manufacturer's tow rating. A truck with a 17,000 lb GCWR that weighs 6,200 lb loaded can tow at most 10,800 lb; with an 11,000 lb tow rating the GCWR is the tighter limit. Every pound added in the truck takes a pound off the trailer.
Worked example
GCWR 17,000 lb, curb weight 5,500 lb, 700 lb of people and gear: loaded truck = 6,200 lb, so the GCWR allows 17,000 - 6,200 = 10,800 lb of trailer. The tow rating is 11,000 lb, so the GCWR is the limit. A 9,000 lb trailer leaves a 1,800 lb margin, and the combination weighs 15,200 lb.
How it works
Max trailer = GCWR - (curb weight + passengers and cargo), capped at the tow rating. The GCWR is the maximum weight of the truck and trailer combined. The maximum trailer towing capacity is the most you can tow when the truck is empty, so any load carried in the truck reduces what you can actually tow. The working limit is the smaller of the two numbers.
The tow rating and the GCWR are not the only limits: the hitch, the rear axle (GAWR) and the payload rating can each stop you first. Check them with the axle weight check and the truck payload calculator. The definitions follow the Alberta guide, which applies to non-commercial towing in Alberta; other provinces and states may differ.
Sources opened 2026-10-16: Alberta Transportation, Recreational Vehicle Towing Guide (GCWR and towing-capacity definitions); Towing - Wikipedia. Planning aid only, not professional, engineering or safety advice. Your vehicle, trailer, hitch and boat manuals and the weight labels on your equipment come first; when in doubt, weigh it at a public scale or ask a qualified professional.
FAQ
What is GCWR?
GCWR (gross combination weight rating) is the maximum weight of the tow vehicle and trailer combined, set by the manufacturer and normally found in the owner's manual.
How do I calculate how much my truck can tow?
Subtract the loaded weight of your truck (curb weight plus passengers, cargo and hitch) from the GCWR, then compare the result with the manufacturer's maximum tow rating. The smaller number is your limit.
Does what I carry in the truck reduce towing capacity?
Yes. The maximum trailer rating assumes an empty truck, so any load carried in the truck reduces the trailer weight you can tow within the GCWR.
Is the tow rating the same as GCWR?
No. The tow rating is the heaviest trailer the manufacturer allows; the GCWR is the maximum for truck and trailer together. Stay under both.
Where do I find my truck's GCWR?
Check the owner's manual or the manufacturer's towing guide for your exact engine, axle ratio and cab configuration. GCWR can change with engine, transmission and differential.