How to Measure Hitch Receiver Size? | Inside Edge Method

To measure hitch receiver size, measure the internal width from inside edge to inside edge of the square opening using a tape measure or caliper.

How to measure hitch receiver size comes down to one simple step: measuring the internal width of the square opening under your vehicle’s rear bumper. But getting it right matters because the receiver size determines which ball mount, bike rack, or other towing accessory fits. Here is exactly how to get it right the first time, with the common mistakes to avoid so you do not end up with an accessory that does not fit.

What Size Is Your Hitch Receiver?

The four most common U.S. receiver openings are 1.25 inches, 2 inches, 2.5 inches, and 3 inches. The number refers specifically to the internal width of the square opening — the distance from one inside wall straight across to the opposite inside wall. This measurement determines the shank size of the ball mount or other hitch accessory your vehicle can accept. A 2-inch receiver is by far the most common on full-size SUVs, trucks, and crossovers, while 1.25-inch receivers typically appear on smaller cars and some compact SUVs.

While the vehicle owner’s manual and hitch class provide useful context, measuring the actual opening is the only way to be certain. Receiver sizes can vary even within the same vehicle model year, and previous owners may have swapped or modified the hitch.

How to Measure It Correctly

Start by cleaning the inside of the receiver tube. Remove any rust, dirt, loose paint, or a reducer sleeve if it can be taken out. A rag or a wire brush works well for clearing debris from the interior walls. These obstructions will make the opening read smaller than it really is, and even a thin layer of rust can throw off a tape measure reading by a noticeable margin.

Use a tape measure, ruler, or caliper to measure the internal width — from inside wall straight across to the opposite inside wall. Do not measure outside-to-outside, corner-to-corner, or diagonally. If a reducer sleeve is installed and cannot be removed, measure the sleeve opening instead, because the accessory must fit the sleeve, not the bare receiver.

Once you have your measurement, round to the nearest standard receiver size. For example, if your tape reads 2.0 inches, you have a 2-inch receiver. If it reads approximately 1.25 inches, that is your size. This measurement tells you the shank size your ball mount or drawbar must have. For ball mount drop or rise, park both the vehicle and trailer on level ground, measure from the ground to the top inside of the receiver tube and to the bottom of the trailer coupler, then subtract the coupler height from the receiver height.

If you already know your receiver size and are looking for the right adjustable hitch, our roundup of heavy duty adjustable receiver hitch options can help you find a setup that fits your vehicle and towing needs.

Mistakes That Lead to the Wrong Size

The most common error is measuring the outside of the receiver instead of the inside — this can be off by half an inch or more and will result in buying the wrong accessory. Measuring with rust, debris, paint, or a reducer sleeve still in place also skews the reading. Guessing the receiver size from the vehicle type rather than measuring directly is another frequent pitfall, as is confusing receiver size with hitch ball diameter or drawbar shank size. For drop or rise measurements, failing to put both the vehicle and trailer on level ground produces inaccurate numbers that can lead to an improperly matched ball mount. Taking a second measurement after cleaning confirms your initial reading and catches any mistakes before you order an accessory.

It is also worth noting that receiver size alone does not determine towing capacity. The hitch class, the ball mount’s weight rating, and the hitch ball’s rating all factor into what you can safely tow. Verify your receiver measurement against the size labeled on any new accessory before installation.