What Is the Towing Capacity Calculator?
This calculator estimates the maximum trailer weight your vehicle can safely tow. It uses the Gross Combined Weight Rating (GCWR) — the maximum allowable weight of your truck, trailer, passengers, cargo, and fluids combined — and subtracts the actual loaded weight of your truck. The result is how much trailer (plus its load) you have left to work with.
How to Use It
Enter your vehicle's GCWR, found in your owner's manual or door-jamb sticker. Then enter the loaded weight of your truck — ideally weighed at a certified scale with passengers, fuel, and cargo onboard. The calculator returns your maximum trailer weight instantly. Always stay within both this figure and your hitch and tire ratings.
The Formula Explained
The core equation is simple subtraction:
$$\text{Max Trailer} = \text{GCWR} - \text{Loaded Truck Weight}$$
Because GCWR caps the combined weight of everything, anything not consumed by your truck is available for the trailer. Adding passengers or cargo to the truck reduces the trailer weight you can pull.
Worked Example
Suppose your truck has a GCWR of 20,000 lbs and, fully loaded with fuel, gear, and people, it weighs 8,000 lbs. Then: $$20{,}000 - 8{,}000 = 12{,}000 \text{ lbs}$$ of maximum trailer weight. If you later add 1,000 lbs of cargo to the truck bed, the truck weighs 9,000 lbs and your max trailer drops to 11,000 lbs.
FAQ
Is towing capacity the same as GCWR? No. GCWR is the total combined limit; towing capacity is what's left after subtracting the loaded truck.
Should I use curb weight or loaded weight? Use the actual loaded weight including passengers, fuel, and cargo for an accurate, safe figure.
Does trailer tongue weight matter? Yes. Tongue weight counts toward the truck's payload and rear axle rating, so check those limits too, in addition to this calculation.
