You should be looking at two factors when choosing the right tongue jack: height and weight capacity.

 

The height is important because you need to have enough height for the jack to lift the coupler to clear the hitch ball on your vehicle. This height measurement on a tongue jack description will typically be referred to as the “extended” height. To figure out the height, you need measure the height from the ground to the bottom of the coupler. This measurement must be done when the trailer is level.

 

The required weight capacity of tongue jack is determined by calculating the tongue weight of your trailer. The rule of thumb for a boat trailer is 7-10% of the weight of your fully loaded trailer. If you have a 6000lb loaded trailer, using 10% as an example, you would require a tongue jack with a capacity of 600lbs. Most tongue jacks on the market will surpass your trailers tongue weight requirement and are not too large or expensive.