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How To Measure for a Trailer Ramp
How-To Article

How To Measure for a Trailer Ramp

By Alex Chiantello
 Posted on October 1st, 2019

Nobody one wants to scrape their low rider, or wrestle with removing the front bumper! Trailer ramps are designed to notch into your existing trailer door to reduce the approach angle, allowing you to drive up into your trailer with no fear of scraping. Here are all the factors that go into finding a trailer ramp that will work for both your vehicle and your trailer.

Step 1

Find your vehicle’s maximum approach angle

So that you can be sure your front bumper won’t hit the ramp on the way up, calculate the maximum ramp angle that will work for your specific vehicle. The easiest way to do that is with a humble yardstick and some basic trigonometry. Lay the 36-inch yardstick between the ground and the tire, and raise it up until it touches the bottom of the front bumper. Then, measure the distance from the highest end of the yardstick to the ground and calculate the angle closest to your tire in degrees. This is the maximum angle of approach your vehicle can accommodate without scraping the front bumper.

Measure Your Trailer Door Length

Measure Your Trailer Door Length

Now that you know the biggest angle of approach that your car can handle, it’s time to measure the length of your trailer’s door length and height off the ground. This will contribute to identifying the trailer ramp length that will work best for your angle of approach and your trailer. Race Ramps has a convenient trailer ramp calculator that will help you visualize your options and provide you with some information about your measurements. Trailer ramp lengths can vary anywhere from 45 inches to 130 inches, however it is ultimately your trailer door measurements and angle of approach that will determine the trailer ramp you need for your vehicle.

Measure the thickness of your trailer door

Measure the thickness of your trailer door

If your trailer door is not as thick as the notch cut-out in the trailer ramp, it will slightly change the angle of approach and you might find yourself in hot water as your car scrapes up into the trailer. Measure the thickness of your door, and when you look for a suitable ramp, make sure the notch is either the same measurement or larger than the thickness of your door.

Make sure the ramp height is suitable

Make sure the ramp height is suitable

The ramp you choose should ideally not be taller than the combined height of the door thickness plus the notch, with an allowance of .5 inches. That is another important reason why we incorporate door height into our trailer ramp calculator.

Step 5 Roll down the windows

Identify if your trailer door has flaps

Flaps could influence the angle that your car drives up the ramp, so if your trailer door ramp does have flaps, you will need to make sure that the ramp you choose has a cut-out to accommodate them. Measure their length, and be conscious of that measurement as you look for trailer ramps. Race Ramps offers two ramps that have 16 inch and 18 inch cut-outs for trailer door flaps.