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Tongue Weight Calculator
Tongue weight is the downward force the trailer coupler puts on your hitch ball. Get it right and the trailer tracks straight behind you; get it wrong and you invite sway or overload the rear of your truck. Enter your loaded trailer weight below to see the recommended range, and add a measured value to check your setup.
Tongue Weight Calculator
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 much tongue weight should a trailer have?
Vehicle manufacturers publish the same rule of thumb in their owner’s manuals and towing guides:
| Trailer type | Recommended weight on the hitch | Example: 6,000 lb loaded trailer |
|---|---|---|
| Conventional (bumper pull, ball hitch) | 10–15% of loaded trailer weight | 600–900 lb |
| Fifth wheel / gooseneck | 15–25% of loaded trailer weight (king pin weight) | 900–1,500 lb |
GMC gives 10–15% for conventional trailers and a wider 15–30% for gooseneck and fifth-wheel trailers. Ford’s F-150 towing material gives 15–25% king pin weight for fifth wheels. Your vehicle and trailer manuals are the final authority.
The formula
Tongue weight range = loaded trailer weight × 0.10 to 0.15 (conventional)
King pin weight range = loaded trailer weight × 0.15 to 0.25 (fifth wheel / gooseneck)
To check a measured value: tongue weight % = measured tongue weight ÷ loaded trailer weight × 100.
Worked example: a travel trailer weighs 6,000 lb loaded and the tongue scale reads 720 lb. 720 ÷ 6,000 = 12%, which is inside the 10–15% range.
Use the loaded weight, not the dry weight
The “dry” or “unloaded vehicle weight” in an RV brochure is the trailer as it left the factory. Water, propane, batteries, food, bikes and camping gear can add over a thousand pounds. Water alone weighs about 8.3 lb per gallon. Run the calculator with the weight you will actually tow; the best number comes from a public scale.
Too little vs. too much tongue weight
- Too light (under ~10%): the trailer’s center of gravity sits too far back, which is a common cause of sway. Move heavy cargo forward of the trailer axles.
- Too heavy (over ~15%): the rear axle of the tow vehicle is overloaded, the front end gets light and steering and braking suffer. Move cargo back toward the axles, or consider a weight distribution hitch if your vehicle maker recommends one.
Tongue weight uses up payload
Everything on the hitch is carried by the tow vehicle, so it counts against payload together with passengers and cargo. A 900 lb tongue on a truck with 1,200 lb of payload leaves only 300 lb for people and gear. Use the towing capacity calculator to see which limit you hit first.
How to measure tongue weight
- Tongue weight scale: place it under the coupler jack or use a hitch with a built-in gauge.
- Public truck scale: weigh the tow vehicle alone, then hitched to the trailer (trailer wheels off the scale pad). The increase on the vehicle’s axles is the tongue weight.
- Always measure with the trailer loaded the way you travel, on level ground.
Frequently asked questions
What percentage of trailer weight should be on the tongue?
For a conventional (bumper-pull) trailer, vehicle makers such as GMC and Ford give 10–15% of the total loaded trailer weight. Fifth-wheel and gooseneck trailers carry more weight on the hitch: Ford guides give 15–25% king pin weight and GMC gives 15–30%. Your owner's manual is the final word.
What happens if tongue weight is too low?
Too little weight on the hitch (below about 10% on a conventional trailer) is a common cause of trailer sway, because the trailer's center of gravity sits behind its axles.
What happens if tongue weight is too high?
Too much tongue weight overloads the rear axle of the tow vehicle, lifts the front axle and reduces steering and braking grip. It also uses up payload capacity, because tongue weight counts as cargo in the tow vehicle.
How do I measure tongue weight?
Use a tongue weight scale or a hitch with a built-in gauge, or weigh the tow vehicle at a CAT scale with and without the trailer hitched (the difference on the drive axle plus steer axle is the tongue weight). Always measure with the trailer loaded the way you will travel.
Does tongue weight count toward payload?
Yes. Tongue weight (or king pin weight) is carried by the tow vehicle, so it must fit inside the vehicle's remaining payload together with passengers and cargo.
Related calculators
Sources
- GMC, “What Is Tongue Weight?” (10–15% conventional, 15–30% gooseneck/fifth wheel)
- Ford, Online Towing Calculator FAQ (10% conventional / 15% fifth wheel and gooseneck assumption)
- Ford, 2026 RV and Trailer Towing Guide (PDF)
This calculator gives general estimates for planning. It is not a substitute for your vehicle and trailer manufacturers’ ratings and instructions. Never exceed any rating on your vehicle, hitch, ball mount or tires.