Anal Toy Sizing Guide

Sizing yourself for anal toys is very different than for vaginal toys. In most cases, it’s all about stretching the anus for anal sex or allowing the user to get larger for using bigger anal toys.

The image below illustrates different dimensions for butt plugs.


Measuring how far the anus can stretch is vital to prevent tearing. So, to do this, you will need: lube, a tapered object and/or a partner. You also need a fabric measuring tape. You can do this sizing solo, but it is difficult to get a good measurement.

The way to do it is to rest on all fours or by leaning over something so you are comfortable. Then, your partner needs to apply plenty of lube to the anus and (the object they are using) or their fingers.

When you are relaxed, they can begin easing into your anus. It is vital not to let them go too far in. This can cause problems with your butt toy.

Once they reach the limit with several fingers or the tapered object, they need to mark how far they inserted. Once they pull their fingers or the object out, you can take the tape and wrap it around the fullest part where they have marked.

This will be the maximum your anus can stretch until you are accustomed to that size. If the manufacturer works in diameter, then divide this number by pi (3.14) to find the width/diameter using a calculator.

How Do You Measure Sex Toys?

Generally speaking, there are four measurements you should be familiar with.

Length: The vertical length of the toy from the two farthest points. We sometimes refer to this as total length as well.

Insertable Length: The length of the toy designed to be safely inserted.

Width (or diameter): The distance between the two sides of the toy.

Girth (or circumference): The circumference of the toy which is relevant to insertable toys.


 Anal Toy Types

  • Anal Douches
  • Anal Vibrators
  • Butt Plugs
  • Glass Butt Plugs
  • Inflatable Butt Plugs
  • Jewel Butt Plugs
  • Large Butt Plugs
  • Princess Plugs
  • Prostate Toys
  • Silicone Butt Plugs
  • Tail Plugs 

Sizing for Anal Douches

Anal douches are intended as a hygienic way of cleaning the rectum for anal play. Because of this, they don’t require sizing for circumference or diameter, and only the length needs to be considered.

Some douches come with maximum insertable lengths of 2 to 4 inches. You can also do the measurement solo, but if a partner can, it will be relatively easier.

anal douche 

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Sizing for Anal Vibrators

Anal vibes can be hard to measure for by yourself, and it can be helpful if you have a partner to assist. The insertable length will be different from the overall length. At this point, there should be a flared base or testicles to stop the vibrator going too far.

Butt vibrators can range from less than 2 inches in circumference, and reach up to over 8 inches.

Finding the length you can insert into your anus can be more difficult. If you already own an anal toy, you can measure the insertable length, or you can choose from the ranges which are more common. Insertable length can be from around 5 inches for smaller models, or up to 12 inches and above for some models. If in doubt, start small.

 anal vibrator

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Sizing for Butt Plugs

Butt plugs are designed to stretch the anus and give a fuller feeling inside the rectum. These need anus sizing for a comfortable depth, and also how wide the anus will be stretched by the broadest part during insertion.

 butt plug

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Sizing for Glass Butt Plugs

Because glass butt plugs will not be as strong as steel, they will come with a thicker neck and shorter insertable lengths that range up to 5 inches. For these, you only need to size up for the circumference of the glass butt plug.

Because these are generally smaller, you can find circumferences of between two and three inches at the small end, and then they range up to between 4 and 5 inches at the top.

 glass plugs

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Sizing for Inflatable Butt Plugs

Sizing yourself for these will only be what the device is like to insert. They are inflatable so the end size can be much more significant. These do come in longer varieties, so anus depth also needs to be measured as well as the circumference.

Ranges of circumference for inflatable butt plugs are found at around 3 inches and can range up to 10 to 12 inches.

 inflatable butt plug

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Sizing for Jewel Butt Plugs

Jeweled butt plugs are mainly made from solid materials so they won't adapt to the body. They also have the flared base that sits between the buttocks. The base will be measured in diameter while the bulb part of the butt plug is measured in circumference.

Their typical insertable lengths are around 4 inches and are pretty standard as penetration is not the focus here.

 jewel butt plug

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Sizing for Large Butt Plugs

What these lack in insertable length, they make up for in circumference. Measuring the anus isn’t so much for what size is comfortable; it’s to see how much you can stretch to fit one of these large butt plugs inside.

Circumferences of large plugs can range from 4 to 5 inches all the way to 9 or 10 inches.

 large butt plug

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Sizing for Princess Butt Plugs

Princess plugs are most often made from stainless steel; this means they will be hard and unforgiving. Finding the right size is vital as they won’t mold to the body during anal insertion.

The neck on these is most often around 1 inch in length, but it is the tapered bulb which stretches the anus on insertion. 

 princess plug

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Sizing for Prostate Massagers

Sizing the anus for a prostate massager is a little different from any other male sex toy. This will take a partner to help as it can make things easier when it comes to taking measurements.

The overall length advertised will be different to insertable length, and it is the insertable portion you need to focus on. Along with this, is the widest part of the prostate massager and what is comfortable when it stretches the anus.

Because the prostate is located a few inches inside the anus, many prostate massagers are in the length range of 4 to 6 inches of insertable length. Girth can range from a slim 2 inches up to a thicker range, around 4 inches. There’s no exact measurement for this.

 prostate massager

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Sizing for Silicone Butt Plugs

Silicone butt plugs are not really designed for long term wear and focus more on stretching the sphincter muscles. Ranges of insertable lengths will range from a little under 5 inches to around 6 inches. Circumference is different and can begin between 2 and 3 inches and range up to 7 inches to 10 inches.

Because of these sizing differences, you do need to size yourself to make sure you find the right stretch and fuller feeling.

 silicone plug

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Sizing for Tail Butt Plugs

Tail butt plugs are designed to be worn for extended periods. For this reason, they are generally a little smaller in circumference so they sit comfortably. It is still crucial to know what size the anus is, so measuring the circumference needs to be done.

Most tail plugs come with around 4 to 5 inches for insertable length, and the circumference ranges from 2.5 inches to approximately 4 inches.

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