Container Home Ideas: Sizes, Layouts and What to Plan For
Hitch Drop / Rise Calculator
A trailer should ride level behind your vehicle. If your receiver sits higher or lower than the trailer coupler, you need a ball mount with the right drop or rise. Two measurements are all it takes.
Hitch Drop / Rise Calculator
Estimates only. Always follow your vehicle's owner's manual, door-jamb label and hitch ratings. Weigh your actual setup at a public scale.
How to measure
- Hitch height (A): park the tow vehicle on level ground and measure from the ground to the top inside edge of the receiver opening.
- Coupler height (B): level the trailer with its tongue jack and measure from the ground to the bottom of the coupler.
- Subtract: A ā B. A positive number is the drop you need; a negative number is a rise.
Rise / drop = hitch height ā coupler height
Examples
| Hitch height | Coupler height | Result |
|---|---|---|
| 21 in (lifted pickup) | 17 in | 4 in drop |
| 12 in (car or crossover) | 13 in | 1 in rise |
| 17 in | 17 in | No drop or rise |
Things to check after hitching
- Squat: tongue weight pushes the rear of the tow vehicle down. Check that the trailer is still level once it’s hitched and loaded.
- Ratings: the receiver, ball mount and hitch ball each have a rating. The lowest one limits your trailer weight and tongue weight.
- Ball size: the ball diameter must match the coupler (it is stamped on the coupler).
- Between sizes: if your result falls between available ball mounts, an adjustable mount lets you fine-tune the height.
Frequently asked questions
How do I measure hitch drop?
Park the tow vehicle and trailer on level ground. Measure from the ground to the top inside edge of the receiver opening (hitch height) and from the ground to the bottom of the level trailer coupler (coupler height). Hitch height minus coupler height is the drop; a negative result means you need a rise.
Why does a trailer need to be level?
A level trailer keeps weight evenly shared between its axles and keeps the hitch geometry as designed. A nose-up or nose-down trailer can shift load, change tongue weight and affect handling and tire wear.
Can I flip a drop ball mount to get a rise?
Many fixed ball mounts can be installed upside down to turn a drop into a rise. Check the ball mount manufacturer's instructions, and remember the ball must be reinstalled facing up.
Should I measure loaded or empty?
Measure on level ground with the trailer level. Then check again with the trailer hitched and loaded, because tongue weight makes the rear of the tow vehicle settle, which can leave the trailer nose-down.
Related calculators
Sources
- etrailer, How to properly measure for a rise and drop on a trailer
- etrailer, Ball mount FAQ
This calculator gives a measurement-based estimate. Follow the instructions and ratings of your hitch, ball mount and vehicle manufacturers.