What each rating means
- Towing capacity: the heaviest trailer the manufacturer rates the truck to pull, for one exact configuration of engine, axle ratio, cab and bed.
- GCWR (gross combined weight rating): the most the truck and trailer may weigh together.
- GVWR (gross vehicle weight rating): the most the truck alone may weigh, including the tongue or pin weight pressing on it.
- Payload: what you can add to the truck as it left the factory. People, cargo, a bed cover and the tongue weight all come out of it.
- Hitch ratings: the trailer weight and tongue weight on the hitch label. Many receiver labels list one pair without weight distribution and another with it. Use the pair that matches how you tow.
You only need the ratings you have. Each one you enter becomes a bar.
How it is calculated
tongue weight = trailer weight × tongue %
towing capacity: trailer weight
GCWR: loaded truck + trailer weight
GVWR: loaded truck + tongue weight
payload: people and cargo + tongue weight
hitch: trailer weight, and tongue weightEach sum is compared with its rating. The rating with the highest percentage used is the limiting one. The heaviest trailer inside every rating solves each line for trailer weight and keeps the smallest.
Worked example
A truck with a 9,000 lb towing capacity, 15,000 lb GCWR, 7,000 lb GVWR and 1,500 lb payload. The hitch label says 10,000 lb and 1,200 lb tongue. The truck weighs 5,900 lb on a scale with 500 lb of people and gear. The trailer weighs 7,000 lb loaded, with 12% tongue weight: 7,000 × 0.12 = 840 lb.
- Towing capacity: 7,000 of 9,000 lb, 78%.
- GCWR: 5,900 + 7,000 = 12,900 of 15,000 lb, 86%.
- GVWR: 5,900 + 840 = 6,740 of 7,000 lb, 96%, 260 lb left.
- Payload: 500 + 840 = 1,340 of 1,500 lb, 89%.
The trailer is well under the towing capacity, yet GVWR is the rating reached first. By GCWR alone the trailer could weigh 15,000 minus 5,900 = 9,100 lb. At 12% tongue weight, payload stops you sooner: (1,500 minus 500) ÷ 0.12 = 8,333 lb.
Where to find your numbers
The GVWR and axle ratings are on the certification label on the driver's door jamb. The payload figure is on the tire and loading label, also on the driver's side door jamb. Towing capacity and GCWR are in the owner's manual or the manufacturer's towing guide for your model year and configuration. The weight of your loaded truck is best taken from a public scale. This page never supplies ratings for any vehicle.
Questions
How do I calculate how much my truck can tow?
Take each rating and solve it for trailer weight: GCWR minus the loaded truck, and payload left divided by the tongue weight %. With a 15,000 lb GCWR and a 5,900 lb truck, GCWR allows 9,100 lb; with 1,000 lb of payload left at 12% tongue weight, payload allows 8,333 lb. The smallest answer is the one that counts.
Does tongue weight count against payload?
Yes. The tongue or pin weight rests on the truck, so it counts against payload and GVWR. An 840 lb tongue plus 500 lb of people and gear uses 1,340 lb of payload.
What is the difference between GVWR and GCWR?
GVWR is the most the truck alone may weigh, including the tongue weight on it. GCWR is the most the truck and trailer may weigh together.
Why can't I tow my full towing capacity?
The towing capacity usually assumes a lightly loaded truck. Once people, cargo and tongue weight are added, GVWR or payload often runs out first. In the example above the trailer uses 78% of the towing capacity but 96% of GVWR.