Trailer Tongue Weight Calculator

The Trailer Tongue Weight Calculator helps you tow safely by finding the ideal tongue weight — the downward force your trailer puts on the hitch. The towing-safety consensus is that tongue weight should be 10-15% of the total loaded trailer weight. Get it right and the trailer tracks straight; get it wrong and you risk dangerous sway (too light) or an overloaded hitch and poor steering (too heavy). Enter your total trailer weight to see the recommended range, or enter a measured tongue weight for an instant safety diagnosis and a cargo-shift recommendation.

What is Trailer Tongue Weight?

Tongue weight (TW) is the static downward force the trailer's coupler exerts on the tow vehicle's hitch ball when the trailer is level and loaded. It is the portion of the trailer's total weight that rests on the hitch rather than on the trailer's own axle(s). Tongue weight is one of the most important — and most overlooked — numbers in safe towing, because it directly controls how stable the trailer is at speed.

Tongue Weight Formula

Tongue weight is calculated as a percentage of the Gross Trailer Weight (GTW), which is the total weight of the trailer plus everything loaded in it.

For example, a fully loaded 5,000 lb trailer should have a tongue weight between 500 lb (10%) and 750 lb (15%), with about 625 lb (12.5%) being an ideal target.

Tongue Weight Percentage Chart

Why Tongue Weight Matters for Safety

Tongue weight controls the trailer's stability. Too little tongue weight shifts the trailer's center of gravity behind its axle, making it act like a pendulum — small steering inputs or crosswinds can start a sway that quickly grows into uncontrollable fishtailing. Too much tongue weight presses the tow vehicle's rear down, lifting the front wheels, which lightens the steering, reduces braking traction, and can overload the hitch and rear axle. The 10-15% range keeps the center of gravity safely ahead of the trailer axle while staying within the vehicle's and hitch's rated capacity.

How to Adjust Your Tongue Weight

How to Measure Tongue Weight

• Tongue-weight scale: A purpose-built scale gives the fastest, most accurate reading.
• Bathroom scale method: For lighter trailers, rest the coupler on a bathroom scale (use a beam and brick setup to keep it at hitch height for heavier trailers).
• Public scale method: Weigh the loaded trailer at a CAT scale with the tongue supported, then again resting on the hitch. The difference is the tongue weight.

How to Use This Calculator

1. Choose your mode and units: Select "Find ideal tongue weight" or "Check a measured tongue weight," then pick pounds or kilograms.
2. Enter the total trailer weight: Use the total loaded weight of your trailer (Gross Trailer Weight).
3. Enter a measured tongue weight (optional): In check mode, enter the value from your scale.
4. Click Calculate: See the ideal range, your tongue-weight percentage, and a safety status.
5. Review the diagram and advisor: The animated load-balance diagram and cargo-shift advisor tell you exactly which way to move your load.

Frequently Asked Questions

What is trailer tongue weight?

Tongue weight is the downward force that the trailer's coupler puts on the tow vehicle's hitch ball. It is the share of the trailer's total weight that rests on the hitch rather than on the trailer's own wheels. Correct tongue weight keeps the trailer stable and is essential for safe towing.

What is the ideal tongue weight percentage?

The widely accepted ideal tongue weight is 10 to 15 percent of the total loaded trailer weight. For most conventional trailers, aiming for about 12 to 13 percent gives a good safety margin and stable, sway-free handling.

How do you calculate tongue weight?

Multiply the total loaded trailer weight by 0.10 to get the minimum tongue weight and by 0.15 to get the maximum. For example, a 5,000 lb trailer should have a tongue weight between 500 and 750 lb. To check a measured value, divide the tongue weight by the total weight and multiply by 100 to get the percentage.

What happens if tongue weight is too low?

If tongue weight is too low, usually below about 9 percent, the trailer becomes prone to sway and fishtailing at highway speed, which is one of the most common causes of towing accidents. The fix is to shift cargo forward, toward the hitch, to add tongue weight.

What happens if tongue weight is too high?

If tongue weight is too high, usually above about 15 to 16 percent, it overloads the hitch and the tow vehicle's rear axle. This makes the front of the vehicle lift, reducing steering and braking control. The fix is to shift cargo rearward, away from the hitch, to reduce tongue weight.

How do you measure trailer tongue weight?

You can measure tongue weight with a dedicated tongue-weight scale, by lowering the coupler onto a bathroom scale (using a beam to keep the load at hitch height for heavier trailers), or by weighing the loaded trailer at a public scale with and without the tongue supported. The tongue weight is the difference.

Additional Resources

• Tongue Weight - Wikipedia
• Towing - Wikipedia