A trailer tongue weight calculator determines the safe tongue weight range for your trailer and tells you which hitch class you need. Tongue weight should be 10–15% of the trailer's Gross Vehicle Weight Rating (GVWR). Too little causes trailer sway; too much overloads the rear axle. Enter your trailer details below to check your setup.
Trailer Details
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Results
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Weight Distribution Hitch Recommended
Tongue weight exceeds 500 lbs. A weight-distribution hitch spreads the load across all four wheels, restoring steering feel and braking performance.
Hitch Classes Reference
| Class | Max Trailer GVWR | Max Tongue Weight | Typical Use |
|---|
How to Calculate Trailer Tongue Weight
Understanding trailer tongue weight is essential for safe towing. An improperly loaded trailer is a leading cause of highway accidents involving tow vehicles. This trailer tongue weight calculator helps you determine the safe weight range and verify your current setup is within spec.
The 10–15% Rule
The universal towing rule is that tongue weight must be 10–15% of the trailer's total loaded weight. For a 6,000 lb GVWR trailer, that is 600 to 900 lbs of tongue weight, with an ideal target around 750 lbs (12.5%). This downward force at the hitch keeps the rear of the tow vehicle down for steering stability.
What Causes Too-Light Tongue Weight
If you load cargo mostly behind the trailer axle, the tongue lifts and tongue weight drops below 10%. This creates a pendulum effect where trailer sway builds on itself at speed. At 60+ mph, trailer sway can be unrecoverable. Load 60% of cargo in front of the trailer axle and 40% behind to maintain proper tongue weight.
Choosing the Right Hitch Class
Hitch class is determined by the heaviest trailer you will tow. Class III (up to 8,000 lbs GVWR) handles most boat trailers, utility trailers, and small campers. Class IV and V are for large fifth-wheel campers and heavy equipment trailers. Your vehicle's owner manual specifies its maximum tow rating — never exceed it regardless of hitch class.
When to Use a Weight Distribution Hitch
When tongue weight exceeds 500 lbs, a weight distribution hitch is strongly recommended. These hitches use spring bars to transfer the downward tongue weight forward to the front axle of the tow vehicle. Without one, heavy tongue weight causes the rear to squat and the nose to rise, reducing front axle contact and steering effectiveness.
FAQ
Is this trailer tongue weight calculator free?
Yes, completely free with no signup required. All calculations run in your browser — no data is sent anywhere.
What is tongue weight and why does it matter?
Tongue weight is the downward force the trailer hitch applies to the tow vehicle's rear hitch receiver. It must be 10–15% of the trailer's total loaded weight (GVWR). Too little tongue weight causes trailer sway, which can be fatal at highway speeds. Too much tongue weight overloads the rear axle and can cause loss of steering control.
How do I measure tongue weight?
The most accurate method is using a tongue weight scale — a bathroom scale with a plank works for lighter trailers. Place the scale under the coupler with the trailer in towing position and measure the downward force. You can also use a hitch weight gauge that inserts between the hitch ball and coupler.
What hitch class do I need?
Hitch class is determined by the trailer's Gross Vehicle Weight Rating (GVWR): Class I up to 2,000 lbs, Class II up to 3,500 lbs, Class III up to 8,000 lbs, Class IV up to 10,000 lbs, Class V for 12,000+ lbs. Always check your vehicle's tow rating in the owner's manual — the hitch class is only one constraint.
What causes trailer sway?
Trailer sway is most commonly caused by insufficient tongue weight (under 10% of GVWR), improper load distribution (too much weight at the rear), overloaded trailer, speed over 55 mph, wind, and passing trucks creating turbulence. A weight-distribution hitch and electronic trailer brake controller help prevent sway for heavier trailers.
Should I use a weight distribution hitch?
Yes, if your tongue weight exceeds 500 lbs or if the trailer's GVWR is more than 50% of the tow vehicle's curb weight. A weight-distribution hitch spreads the tongue weight across all four wheels of the tow vehicle, restoring steering feel and improving brake performance.