AxleTally

AxleTally → GCWR Calculator

GCWR Calculator

Turn your gross combined weight rating into a real number: how much trailer you can safely tow once the truck is loaded.

Your weights

Use your actual scaled numbers, not the brochure curb weight.

Loaded weight = scaled truck + passengers + cargo + full fuel.

Key takeaways

  • Max trailer weight = GCWR − loaded vehicle weight.
  • GCWR covers everything: truck, passengers, cargo, fuel, trailer, and trailer load.
  • Use your actual scaled weight from a CAT scale, not the brochure curb weight.
  • Aim for 10–15% of trailer weight on the tongue for stable, sway-free towing.

What is GCWR?

GCWR (gross combined weight rating) is the maximum allowable weight of your fully loaded tow vehicle and trailer combined. That single number is set by the manufacturer and accounts for everything the powertrain, brakes, and frame can safely handle: the truck itself, every passenger, all cargo, a full tank of fuel, the trailer, and everything loaded on it. Your trailer capacity is simply whatever is left after you subtract the truck's loaded weight.

Max trailer weight (lb) = GCWR − Loaded vehicle weight Vehicle share of GCWR (%) = Loaded vehicle weight ÷ GCWR × 100 Suggested tongue weight (lb) = Max trailer weight × 0.12

The reason loaded weight matters so much: every pound you add to the truck — a fifth passenger, a bed full of gear, a full fuel tank — is a pound subtracted from your towing budget.

Worked example: 13,000 lb GCWR

With a GCWR of 13,000 lb and a loaded vehicle weight of 6,200 lb, your max trailer weight = 13,000 − 6,200 = 6,800 lb. The truck already uses 6,200 ÷ 13,000 = 47.7% of the combined rating, and a sensible tongue-weight target is 12% of 6,800 ≈ 816 lb.

Weight-rating glossary

TermWhat it means
GVWRMax weight of the loaded tow vehicle alone.
GCWRMax weight of the tow vehicle and trailer combined.
GAWRMax weight allowed on a single axle (front or rear).
Curb weightVehicle weight empty — no passengers or cargo.
PayloadGVWR minus curb weight: people plus cargo the truck can carry.
Tongue weightDownward force the trailer coupler puts on the hitch.

Using your number safely

GCWR is a ceiling, not a target — leave headroom for grades, heat, and a margin of error in your weights. Confirm the trailer you want is within range with the towing capacity calculator, then make sure the load sits right on the hitch using the tongue weight calculator. Both work hand-in-hand with the GCWR limit you found here.

Frequently asked questions

What is GCWR?

The gross combined weight rating is the maximum allowable weight of your fully loaded tow vehicle and trailer combined. Subtract loaded vehicle weight from GCWR to find your trailer capacity.

GCWR vs GVWR?

GVWR is the max weight of the tow vehicle alone; GCWR is the max weight of that vehicle plus its trailer. GCWR is always the larger figure.

How do I find my GCWR?

It's in the owner's manual and the towing guide for your exact trim and engine; some trucks also print it on the driver's door jamb sticker.

How do I weigh my loaded truck?

Drive it fully loaded — passengers, cargo, full fuel — across a certified CAT scale at a truck stop and use that actual weight.

What happens if I exceed GCWR?

You overload the engine, transmission, brakes, and frame — longer stops, overheating on grades, faster wear, and possible voided warranty. Never exceed it.

Does GCWR include passengers and cargo?

Yes — truck, passengers, cargo, fuel, trailer, and trailer load all count, which is why you use scaled loaded weight, not curb weight.

Weight ratings are set by the vehicle manufacturer; always confirm yours against the official manufacturer towing guide and weigh your rig at a certified scale before towing.

Last reviewed June 2026

Note: educational estimate only. GCWR, GVWR, and axle ratings are firm safety limits — never exceed your rated limits. Verify every figure against your owner's manual and scaled weights before towing.

Result

Max trailer weight

lb
Vehicle share of GCWR
Remaining capacity
Suggested tongue weight