What Size Butt Plug Should I Start With?

If you are looking at butt plugs and wondering whether “Small” really means small, you are not alone.

Size names are not always consistent between brands. One company’s Small may be close to another company’s Medium, while a toy described as “beginner-friendly” may still look much fuller than you expected.

The simplest approach is to check the widest diameter of the insertable part and then consider the shape, firmness and length.

For a first butt plug, begin your search within the Small range. You are not trying to find the biggest size you can manage. You are looking for something that lets you relax, stay in control and enjoy discovering the sensation.

Butt Plug Sizes at a Glance

Anal Sex Toys Shop uses the following size ranges:

These measurements refer to the widest diameter of the insertable body—not the base.

They are designed to make products easier to compare. They do not mean that every Small plug will suit every beginner or that an experienced user should automatically choose Large.

What Is a Good First Butt Plug Size?

If you have no previous anal-play experience, start by comparing plugs within the Small range.

For many first-time shoppers, approximately 25 to 30 mm is a useful area to explore. You may prefer something slimmer if you want a particularly gentle introduction, and there is nothing wrong with that.

The right first plug should look inviting rather than intimidating. Along with the diameter, look for:

• A slim tip
• A smooth, gradual taper
• A manageable insertable length
• A secure flared base
• A material and firmness that appeal to you

A flexible, gradually tapered 30 mm silicone plug may feel more approachable than a rigid 27 mm plug with a blunt tip and broad shoulder. The size label is only the beginning of the story.

Browse our Small Butt Plugs or read the Beginner Butt Plug Guide if you also need help comparing shapes and materials.

How to Read Butt Plug Measurements

Don’t let a row of measurements take the fun out of choosing. Start with just one number: the widest diameter.

That number gives you the best idea of how full the plug may feel. The other measurements simply help you understand how deep it sits, how it stays in place and whether the base will feel comfortable.

Start With the Widest Diameter

The widest diameter is measured straight across the fullest insertable part of the plug. It is also the measurement we use for our size categories:

• Up to 30 mm: Small
• Over 30 mm and under 40 mm: Medium
• 40 mm to under 50 mm: Large
• 50 mm and above: XL

If you are choosing your first plug, this is the number worth checking before anything else.

Then Look at the Length

Insertable length tells you how deeply the plug can sit. A long, slim plug offers more depth without necessarily creating more fullness, while a shorter, wider plug can feel fuller closer to the entrance.

Make sure the listing shows insertable length, not just total length. Total length may also include the base, handle or tail.

Notice the Neck and Base

The neck is the slimmer section just above the base. A narrower neck may let the plug settle more comfortably, while a thicker neck can keep the sensation more noticeable.

The base remains outside the body. It should be securely flared or shaped to keep the toy from slipping fully inside, but it should also look comfortable for the way you want to play.

Diameter Is Not Circumference

If a measurement looks surprisingly large, check whether it is circumference. Diameter goes straight across the toy; circumference goes all the way around it.

A 30 mm-diameter plug has a circumference of about 94 mm, but it is still only 30 mm wide. Our Small–XL size ranges always use diameter.

Keep it simple: choose by diameter first, then use the length, neck and base to refine the fit.

Why Diameter Isn’t the Whole Story

Two plugs can share a similar size label—or even the same listed diameter—and still feel completely different.

One may have a slim tip, a long taper and flexible silicone. Another may have a rounded body, a sudden shoulder and firm metal. On paper, the measurements can look reassuringly similar. In use, the experience may be nothing alike.

• Taper: A gradual taper lets the width increase slowly. A sudden shoulder can feel more intense.
• Firmness: Flexible silicone can feel more forgiving, while firm silicone, metal and glass create more precise pressure.
• Texture: Ridges and bumps add stimulation and can make a toy feel more demanding than a smooth plug.
• Length: More length creates depth, even when the plug is relatively slim.
• Weight: A metal plug can feel heavier and more noticeable than a silicone plug of the same diameter.

This is why “beginner-friendly” cannot be defined by diameter alone.

Why a Training Set’s Large Plug May Still Be Medium

Training sets often call their pieces Small, Medium and Large. Those names usually show how the toys compare within that particular set.

For example, our Black Curved Silicone Anchor Butt Plug Training Set contains:

• Small: 24 mm wide
• Medium: 28 mm wide
• Large: 36 mm wide

The 36 mm toy is the largest piece in the set, so its option name is Large. When compared with the entire Anal Sex Toys Shop catalogue, however:

• 24 mm is Small
• 28 mm is Small
• 36 mm is Medium

Neither label is wrong. The set name tells you which piece comes next, while the sitewide category lets you compare it with other products.

Whenever a label seems confusing, trust the exact diameter.

How to Choose Without Overthinking It

Start by deciding what you want the plug to feel like. Are you looking for a gentle introduction, noticeable fullness, vibration, extra weight or something you can wear with a partner?

1. Begin with a realistic diameter.
2. Check how gradually the plug widens.
3. Compare insertable length separately from width.
4. Consider whether you want flexible or firm pressure.
5. Make sure it has a secure external base.
6. Use plenty of compatible lubricant and take your time.

For a first experience, it is usually easier to keep the design simple. You can always explore more width, texture, weight or vibration once you know what you enjoy.

Need help with preparation, lubrication and insertion? Read How to Use a Butt Plug Correctly.

When Should You Move Up a Size?

There is no correct schedule.

Consider more fullness when your current plug feels comfortable and you genuinely want a stronger sensation.

Compare the exact diameters before buying. Moving from 28 mm to 32 mm is a much smaller change than moving from 30 mm to 39 mm, even though both could be described as moving from Small to Medium.

You also do not have to progress. If you find a size you love, you are allowed to stay there.

For more help with pacing and gradual sizing, visit our Anal Training Guide.

Butt Plug Size FAQ

Is a 30 mm butt plug Small?

Yes. On Anal Sex Toys Shop, a plug measuring exactly 30 mm at its widest insertable point is Small. Anything over 30 mm and under 40 mm is Medium.

Is a 35 mm plug suitable for beginners?

A 35 mm plug is Medium in our size system. It may suit someone with previous experience, especially if it has a flexible material and gradual taper. A completely new user will usually find more approachable options in the Small range.

Does a longer plug count as a larger size?

No. We use The Small–XL categories are based on widest diameter. Length affects depth and should be compared separately.

How much bigger should my next plug be?

There is no perfect increase that works for everyone. Compare the exact diameter with your current plug and choose a change that feels gradual rather than dramatic.

What if using a plug hurts?

Do not force it or try to push through sharp or increasing pain. Slow down, use more compatible lubricant or stop and return to a size that feels comfortable.

Seek appropriate help if you experience significant or persistent pain or bleeding, or if a toy cannot be removed safely.

Ready to Find Your Size?

If you are choosing your first plug, start with our Small Butt Plugs collection and compare the exact measurements of the products that appeal to you.

Your ideal plug is not the one with the most impressive label. It is the one that leaves you feeling comfortable, confident and eager to play again.

Last reviewed: 2 September 2026