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Standard Trailer Hitch Ball Sizes | How to Choose

The Standard Trailer Hitch Ball Sizes

There are four standard trailer ball sizes: 1-7/8", 2", 2-5/16" and 3". These measurements refer to the diameter of the trailer ball. Standardized tow ball sizes allow for easier coupling and towing.

In this guide, we will cover how to measure a trailer ball, what size trailer ball to select for your vehicle and what the most common trailer ball size is.


4 Standard Trailer Ball Sizes:

1-7/8-Inch Trailer Hitch Ball1-7/8-Inch Trailer Hitch Ball

1-7/8-inch diameter

Light-duty towing

2-Inch Trailer Hitch Ball2-Inch Trailer Hitch Ball

2-inch diameter

Medium-duty towing

2-5/16-Inch Trailer Hitch Ball2-5/16-Inch Trailer Hitch Ball

2-5/16-inch diameter

Heavy-duty towing

3-Inch Trailer Hitch Ball3-Inch Trailer Hitch Ball

3-inch diameter

Gooseneck towing


How to Choose a Trailer Ball Video


What Size Trailer Ball Do I Need?

The size of the trailer ball needed for your towing setup will be determined by three things: your coupler size, trailer ball hole diameter and your towing capacity.

In short, your trailer ball diameter must match your coupler size, the shank diameter must fit the ball hole and the weight capacity must be enough to safely tow your trailer.

  1. Match the ball diameter to the coupler size
  2. Match the shank to the trailer ball hole
  3. Match the weight capacity of your towing system

 

Step 1: Match the Ball to the Coupler Size

When choosing a trailer ball, first select the ball diameter by matching it to the coupler size. Most manufacturers stamp or label the correct trailer ball size on the coupler.

Make sure that your coupler and trailer ball have a solid connection before towing and that all necessary adjustments have been made.

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Trailer Coupler Size for BallTrailer Coupler Size for Ball

Step 2: Match the Shank to the Trailer Ball Hole

The hole in the platform of a ball mount or bumper hitch is where the trailer ball bolts onto. It is important to know the diameter of this hole so that you can choose a trailer ball with a matching shank diameter.

If the trailer ball shank is too small, it will shift while towing and likely come loose. If the shank size is too small for the trailer ball hole, you may be able to use a reducer bushing to make up the difference.

Trailer Ball Shank DiameterTrailer Ball Shank Diameter

Step 3: Match the Weight Capacity of Your Towing System

When selecting a trailer ball or any towing accessory, weight capacity must always be considered. The weight rating for a trailer ball will be listed as the ball capacity. Note that this will reflect the gross trailer weight limit, not the tongue weight.

You must select a trailer ball with a ball capacity that exceeds the gross weight of your trailer.

Trailer Hitch Ball CapacityTrailer Hitch Ball Capacity

 

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How to Measure Trailer Ball Size

Trailer balls have four key measurements: ball diameter, shank length, shank diameter and rise.

The ball diameter is the diameter of the trailer ball sphere itself. The shank length is the total distance of the threaded stem. The shank diameter is the diameter of the threaded stem, and the rise is how high the trailer ball sits off of its base.

How to Measure Trailer Hitch Ball Size - DiagramHow to Measure Trailer Hitch Ball Size - Diagram

Trailer Ball Size Chart

Ball Diameter Shank Length Shank Diameter Weight Capacity
1-7/8" 1-5/8" to 3" 3/4" to 1" 2,000 to 3,500 lbs. GTW
2" 1-3/4" to 3" 3/4" to 1-1/4" 3,500 to 12,000 lbs. GTW
2-5/16" 2-1/8" to 3-1/2" 1" to 2" 6,000 to 30,000 lbs. GTW
3" 3-1/4" 2" 30,000 lbs. GTW
*Weight capacities and dimensions vary by part number. Verify specifications before purchase / towing.


Most Common Trailer Ball Size

Perhaps the most common hitch ball size is the 2-inch ball. This is because 2-inch trailer balls are the best fit for most class 3 hitches, and class 3 hitches are the most popular trailer hitch.

Despite this fact, each towing setup is different, and there is no one-size-fits-all, universal trailer ball. For your own towing setup, make sure you choose the ball the best fits your coupler, ball mount and weight requirements.

Most Common Trailer Ball Size - 2-Inch or 2-5-16-InchMost Common Trailer Ball Size - 2-Inch or 2-5-16-Inch
Truck Towing Travel Trailer CamperTruck Towing Travel Trailer Camper

Travel Trailer Hitch Ball Size

The hitch ball used to tow most travel trailers is a 2-inch or 2-5/16-inch trailer ball. Travel trailers can weigh anywhere from 5,000 to 10,000 lbs. or more, and the 2-inch to 2-5/16-inch ball weight ratings provide a perfect match.

Additionally, many travel trailers are pulled using a weight distribution hitch. Most WD hitches come standard with a 2-5/16-inch ball.


FAQs

What is the standard ball size for a trailer hitch?

The standard ball size for a trailer hitch is 2 inches in diameter. Most trailers have a 2-inch coupler, making the 2-inch ball the standard size.

However, the ball size may be different depending on the size of the trailer. The other common ball sizes include 1-7/8 inches and 2-5/16 inches.

 

What are the different sizes of trailer hitch balls?

The different sizes of trailer hitch balls are 1-7/8-inch, 2-inch, 2-5/16-inch and 3-inch. 1-7/8-inch hitch balls are for light-duty trailers, 2-inch are for medium trailers, 2-5/16-inch are for heavy trailers and 3-inch are for gooseneck trailers.

There is also a 50mm hitch ball size that is more common for European trailers.

 

Should the ball hitch and coupler be the same size?

Yes, the ball hitch and coupler should be the same size. This means the diameter of the trailer ball should be exactly the same as the inside opening of the coupler. You can find these measurements stamped into the components themselves.

If the ball hitch and coupler are different, it can create an unsafe towing situation that may lead to a vehicle-trailer disconnect. Some couplers can be adjusted to help eliminate play in the ball connection.

 

What is the most common size trailer hitch ball?

The most common size trailer hitch ball is the 2-inch diameter ball. The 2-inch ball is used on a variety of popular trailers, such as boat trailers, utility trailers and campers. 2-inch trailer balls have a wide weight capacity range from 3,500 pounds to 12,000 pounds gross trailer weight.

 

Are there different size tow balls?

Yes, there are four different size tow balls commonly used for towing: 1-7/8-inch, 2-inch, 2-5/16-inch and 3-inch diameter. One size will not fit all trailers.

1-7/8-inch tow balls are rated as high as 3,500 pounds and are used for towing small, light-duty trailers. On the other hand, 2-5/16-inch balls can be rated for as much as 30,000 pounds to tow large, commercial and agricultural trailers.

 

How do you measure hitch ball size?

You measure hitch ball size starting with the diameter of the ball itself. The diameter should be stamped into the top of the ball, or you can use a tape measure or ruler to find the measurement yourself. Use the diameter to match your trailer coupler.

Next, measure the hitch ball shank size. Find the diameter of the shank and the length, taken from the bottom of the base to the end of the threads.

Finally, measure the thickness of the base. This is how much rise the trailer ball will add to your hitch connection.

 

What is the smallest trailer hitch ball?

The smallest trailer hitch ball is the 1-7/8-inch ball diameter. This ball size has a weight capacity of up to 2,000 or 3,500 pounds, depending on the individual ball. It has a shank diameter or 3/4 inches or 1 inch.

The 1-7/8-inch ball is common for light-duty towing. It is used on cars, minivans and crossover vehicles to tow small trailers, such as utility trailers, teardrop campers and fishing boat trailers.

 

What size are trailer hitch balls?

Trailer hitch balls come in four different sizes: 1-7/8, 2, 2-5/16 and 3 inches. They also come with different shank or stem sizes, ranging from 3/4 inches to 2 inches in diameter.

Depending on the ball size, weight capacities for trailer hitch balls range from 2,000 up to 30,000 pounds. Each sizes is designed for different types of trailers and towing applications.

 

What size ball does my trailer need?

A trailer needs to have a ball that perfectly matches the size of its coupler. First, find the trailer coupler sizes stamped somewhere on the coupler itself. You can also use a ruler or tape measure to measure the inside opening of the coupler. This measurement is the size of the trailer ball needed. The coupler opening size must match the diameter of the trailer.