Key takeaways
- Towing capacity is capped by GCWR — the most your truck and loaded trailer can weigh combined.
- Payload = GVWR − curb weight, and tongue weight counts against payload.
- Max trailer ≈ GCWR − curb weight − passengers and cargo.
- Aim for tongue weight of 10–15% of trailer weight, and confirm every number against your door jamb and owner's manual.
The five ratings that decide what you can tow
"Towing capacity" isn't one number — it's the result of several weight limits working together. Understanding each one keeps you from quietly overloading a single component:
- GVWR (Gross Vehicle Weight Rating) — the maximum your tow vehicle is allowed to weigh fully loaded, including passengers and cargo.
- GCWR (Gross Combined Weight Rating) — the maximum allowed weight of the truck and the loaded trailer together. This is the ceiling that sets real-world towing capacity.
- Curb weight — what the truck weighs empty, with fluids and a full tank but no people or cargo.
- Payload — everything you add to the empty truck: passengers, cargo, accessories, and the trailer's tongue weight.
- Tongue weight — the downward force the trailer coupler puts on the hitch. Too little causes sway; too much overloads the rear axle.
The core formulas
Three quick equations turn those ratings into the numbers you actually need before hooking up:
Start with the towing capacity calculator to find your safe trailer limit, double-check the combined ceiling with the GCWR calculator, and once you know your trailer's loaded weight, size the hitch load with the tongue weight calculator.
Glossary of weight ratings
| Term | What it means |
|---|---|
| GVWR | Max loaded weight of the tow vehicle alone |
| GCWR | Max combined weight of vehicle + loaded trailer |
| Curb weight | Empty vehicle weight with fluids, no people or cargo |
| Payload | GVWR minus curb weight — passengers, cargo, and tongue weight |
| Tongue weight | Downward hitch force, ideally 10–15% of trailer weight |
| Towing capacity | Max trailer the rig can pull without exceeding GCWR |
A worked example
Say your truck has a GVWR of 7,000 lb, a curb weight of 5,500 lb, and a GCWR of 13,000 lb, and you're carrying 600 lb of passengers and cargo. First the payload:
So you have 1,500 lb of payload and can pull roughly 6,900 lb of trailer with that load aboard. Note how the 600 lb of people and gear directly reduces the trailer figure — and remember the trailer's tongue weight (about 690–1,035 lb at 10–15% of 6,900 lb) also lands on the payload, so it must fit inside that 1,500 lb.
Verify before you hitch up
These formulas give you a planning estimate, not permission. Never exceed the ratings printed on the door-jamb placard or in your owner's manual, which reflect your truck's exact engine, axle ratio, and trim. The only way to know your real loaded weights is to drive the fully packed rig across a certified scale — most CAT scales at truck stops will weigh your truck and trailer axles for a few dollars. Compare those readings against GVWR and GCWR before every big tow.
Frequently asked questions
How do I find my truck's towing capacity?
Check the towing section of your owner's manual and the placard inside the driver's door jamb — they list the GVWR, GCWR, and rated tow weight for your exact configuration. Don't trust the headline marketing number, which usually applies to a stripped base-spec truck.
What's the difference between GVWR and GCWR?
GVWR is the maximum weight of the tow vehicle alone (with passengers and cargo). GCWR is the maximum weight of the vehicle and loaded trailer combined. Towing capacity is limited by GCWR.
Does payload include passengers?
Yes. Payload is everything added to the empty truck — passengers, cargo, accessories, and the trailer's tongue weight all count against it.