Towing Capacity Calculator

The towing number in a truck brochure is a best case. Your real limit is the lowest of four ratings: the manufacturer’s tow rating, the GCWR, your remaining payload and your hitch. This calculator checks all four and shows which one limits you.

Estimates only. Always follow your vehicle's owner's manual, door-jamb label and hitch ratings. Weigh your actual setup at a public scale.

How the calculation works

The calculator works out the maximum loaded trailer weight allowed by each rating and keeps the lowest one:

Check	Formula
Tow rating	Maximum trailer weight from the owner’s manual or towing guide for your exact configuration
GCWR	GCWR − (curb weight + passengers + cargo)
Payload	(GVWR − curb weight − passengers − cargo) ÷ tongue share
Hitch	Rating stamped on the receiver / ball mount (the lowest-rated part counts)

The tongue share is 10% for conventional trailers and 15% for fifth-wheel and gooseneck trailers, the same assumption Ford uses in its online towing calculator. If your trailer carries more weight on the hitch, your payload limit will be lower. Use the tongue weight calculator to check.

Worked example

A half-ton pickup is rated to tow 9,000 lb. GCWR is 15,000 lb, GVWR is 7,000 lb, and it weighs 5,200 lb with a full tank. Two adults, a cooler and tools add 600 lb.

Loaded vehicle: 5,200 + 600 = 5,800 lb
GCWR check: 15,000 − 5,800 = 9,200 lb
Payload left: 7,000 − 5,800 = 1,200 lb → 1,200 ÷ 0.10 = 12,000 lb
Tow rating: 9,000 lb ← the limit

Add a family of four and a bed full of gear (another 600 lb) and the picture changes: the GCWR check drops to 8,600 lb and payload left drops to 600 lb, which limits a conventional trailer to about 6,000 lb. That is why the same truck can be “rated for 9,000 lb” and still be overloaded with a 7,000 lb camper.

Where to find each number

GVWR is on the certification label on the driver’s door jamb. The tire and loading information placard next to it shows the maximum combined weight of occupants and cargo.
GCWR and tow rating are in the owner’s manual or the manufacturer’s towing guide. They depend on engine, axle ratio, cab, bed and towing package, so look up your exact configuration.
Curb weight is listed in the towing guide, but options and accessories add weight. Weighing your vehicle with a full tank at a public scale gives the true number.
Hitch rating is stamped on the receiver and on the ball mount and ball. The lowest rating applies.

Glossary

GVWR (Gross Vehicle Weight Rating): Maximum the vehicle may weigh, including passengers, cargo and tongue weight.
GCWR (Gross Combined Weight Rating): Maximum the vehicle and loaded trailer may weigh together.
Payload: GVWR minus curb weight: what the vehicle can carry, including the tongue weight of a trailer.
Curb weight: The vehicle with standard equipment and fluids, including a full tank of fuel, but no passengers or cargo.

Frequently asked questions

Is the advertised towing capacity what I can actually tow?

Usually not. The maximum towing figure in brochures is calculated for a lightly loaded truck with a specific configuration. Passengers, cargo and accessories all reduce what you can tow, because the truck and trailer together must stay under the GCWR and the tongue weight must fit within the remaining payload.

What is GCWR?

Gross Combined Weight Rating is the maximum allowed weight of the tow vehicle and the loaded trailer together, including all passengers and cargo. It is set by the vehicle manufacturer and listed in the owner's manual or towing guide.

Where do I find GVWR and curb weight?

GVWR is printed on the certification label on the driver's door jamb. Curb weight is in the owner's manual or the manufacturer's towing guide; the most accurate number comes from weighing your own vehicle, full of fuel, at a public scale.

Why does payload limit towing?

Tongue weight is carried by the tow vehicle. Ford's towing calculator, for example, assumes 10% of trailer weight on the tongue for conventional trailers and 15% for fifth-wheel/gooseneck. If your remaining payload is 800 lb, a conventional trailer heavier than about 8,000 lb would overload the truck even if the tow rating is higher.

Should I tow at 100% of my capacity?

This calculator shows the legal and rated limit, not a comfortable target. Many experienced towers leave a margin below the limit for wind, hills and braking. Always follow your vehicle manufacturer's guidance.

Related calculators

Sources

Ford, Online Towing Calculator FAQ (GCWR limit, 10%/15% tongue load assumption)
Ford, 2026 RV and Trailer Towing Guide (PDF, definitions of GVWR, GCWR, payload)
eCFR, 49 CFR 571.110 — tire and loading information placard

This calculator gives general estimates for planning. It does not replace your vehicle manufacturer’s ratings. Never exceed GVWR, GCWR, axle ratings (GAWR), tire ratings or hitch ratings. Brakes, mirrors and trailer brake controller requirements vary by state and trailer weight.