Tongue weight is the downward force the trailer tongue exerts on your hitch ball. For safe towing, it should be 10-15% of your total trailer weight. Too little causes sway, too much overloads your vehicle.
What Is Tongue Weight and Why Does It Matter?
Tongue weight is measured by placing the trailer tongue on a scale while the trailer is level. It affects stability, braking, and steering. A proper tongue weight keeps the trailer tracking straight and prevents dangerous sway at highway speeds. Most vehicle hitches have a maximum tongue weight rating, often 10% of the tow rating. Exceeding this can damage your hitch or cause loss of control.
How to Measure Tongue Weight
Use a dedicated tongue weight scale or a bathroom scale with a pipe and board setup. Park the trailer on level ground, disconnect from the vehicle, and place the scale under the coupler. Adjust the trailer jack so the coupler is at hitch height. Read the weight. For accuracy, repeat three times and average the readings. Alternatively, use a Sherline or similar scale designed for this purpose.
How to Adjust Tongue Weight
If tongue weight is too low (under 10%), move cargo forward in the trailer. If too high (over 15%), shift cargo rearward. Avoid exceeding 15% as it can overload the rear axle and cause poor steering. For travel trailers, water and propane tanks affect weight; fill tanks before measuring. Always re-measure after making adjustments. For boats, ensure the motor is trimmed up and fuel tanks are positioned correctly.
Common Mistakes First-Time Towers Make
Many new towers ignore tongue weight entirely, leading to sway. Others overload the tongue with heavy items like generators or spare tires. Always account for the weight of the trailer itself (dry weight) plus cargo. Use a weight distribution hitch if tongue weight exceeds your vehicle’s rating. Never exceed your hitch’s maximum tongue weight, even if the trailer is lighter overall.
Frequently Asked Questions
What happens if tongue weight is too low?
Low tongue weight (under 10%) causes trailer sway, especially at higher speeds or in crosswinds. This can lead to loss of control and accidents. Always aim for at least 10%.
Can I use a bathroom scale to measure tongue weight?
Yes, but you need a method to support the tongue on the scale. Place a short 2×4 under the coupler and the scale on a flat surface. Ensure the trailer is level. This works for lighter trailers under 500 lbs tongue weight.
Does tongue weight change when I load the trailer?
Yes, cargo position affects tongue weight. Placing heavy items forward increases it, rearward decreases it. Always measure after loading and before towing. Recheck if you add or remove significant weight.
The Bottom Line
Tongue weight is a critical safety factor that every tower must understand. Measure it before every trip and adjust loading to stay within 10-15% of total trailer weight. For more towing tips and gear recommendations, check out our towing category and our guide to the best jump starters for roadside emergencies.
