Tongue Weight (TW)

The downward pressure placed on the ball by the coupler.

Trailer Loading
One of the main causes of trailer sway is not having a large enough percentage of trailer tongue weight compared to gross trailer weight.  Usually tongue weight is 10 to 15 percent of the trailer's gross weight.  To help prevent the trailer from swaying back and forth, a few things can be done. Try placing heavier cargo in the front of the trailer, ahead of the trailer's axle.  Also center the cargo left-to-right and use tie-downs to keep the load from sliding.

The best way to verify your tongue weight is to run it across a certified scale. However, you can also use a bathroom scale using the method described below:

Normally the TW can be measured using a bathroom scale and a box.  On a level surface, place the coupler of the loaded trailer on the scale at normal towing height (not pictured). For heavier tongue weights, use the method diagramed on the right. There is another alternative method described on the Boat US Trailering website.