What the animation shows
The animation and the step-by-step video above use your numbers. Here is the same walkthrough written out for the default example.
What you enter
- Vehicle curb weight (or scale weight, empty): 5000 lb. Best: weigh the empty truck with a full tank at a CAT scale.
- Passengers and cargo in the vehicle: 400 lb. People, tools, gear and hitch hardware.
- Loaded trailer weight: 6000 lb. Actual loaded weight, not the trailer’s empty weight.
- Tongue weight percentage: 12 %. Conventional trailers: 10–15%. Fifth-wheel/gooseneck: 15–25%.
- Vehicle GVWR: 7000 lb. Door-jamb sticker.
- Vehicle GCWR: 14000 lb. Owner’s manual or towing guide.
- Manufacturer tow rating: 9000 lb.
What happens, step by step
- The empty 5,000 lb truck fills the first part of each bar.
- People and gear add 400 lb, all counted against payload.
- The trailer hitches on, and 720 lb of tongue weight rides on the truck.
- The full 6,000 lb trailer counts toward GCWR and the tow rating.
- Every bar stays under its line, with 880 lb payload left.
The answer: payload remaining (gvwr margin) is 880 lb.
How it’s calculated
- Tongue weight = trailer weight × tongue %
- Loaded vehicle = curb + passengers/cargo + tongue weight → compare with GVWR
- Combined = curb + passengers/cargo + trailer → compare with GCWR
- Trailer weight → compare with tow rating
Worked example
5,000 lb truck with 400 lb of people and gear pulling a 6,000 lb trailer at 12% tongue weight; GVWR 7,000, GCWR 14,000, tow rating 9,000 lb.
Inputs
- Vehicle curb weight (or scale weight, empty)
- 5000 lb
- Passengers and cargo in the vehicle
- 400 lb
- Loaded trailer weight
- 6000 lb
- Tongue weight percentage
- 12 %
- Vehicle GVWR
- 7000 lb
- Vehicle GCWR
- 14000 lb
- Manufacturer tow rating
- 9000 lb
Results
- Payload remaining (GVWR margin)
- 880 lb
- Tongue weight
- 720 lb
- Loaded vehicle weight
- 6,120 lb
- Gross combined weight
- 11,400 lb
- GCWR margin
- 2,600 lb
- Tow rating margin
- 3,000 lb
- Payload used
- 56%
Assumptions and limits
- Tongue weight is part of the trailer’s weight, so it is counted once in the combined weight.
- Rear axle rating (GAWR) is not checked — weigh axles individually at a scale.
- No vehicle specifications are assumed; all ratings come from you.
Verify the result against the applicable local code, adopted code edition, manufacturer instructions and project requirements. See our methodology.
Questions
Why is payload more important than tow rating?
Tow ratings are often calculated with a nearly empty truck. Adding passengers, gear and 10–15% tongue weight can exceed GVWR long before the trailer reaches the tow rating.
Where do I find GVWR and GCWR?
GVWR is on the driver’s door-jamb sticker. GCWR is in the owner’s manual or the manufacturer’s towing guide for your exact configuration.