Why It’s Important To Know How To Measure For A Chastity Cage

Whether you're just starting out in chastity play or you're a seasoned wearer, knowing how to measure for a chastity cage is essential to finding the perfect fit. A poorly sized cage can lead to discomfort, pinching, or even long-term frustration, but with the right measurements, you’ll enjoy a snug, secure fit from day one.

We often get asked how to measure a cock cage, and the good news is, it’s easier than you think. With just a few simple tools and a bit of patience, you can ensure a safe and pleasurable experience, whether it’s your first cage or your fifth.

At Chastity Cages Co, we offer a wide range of cages in different shapes and sizes to suit nearly every body type. From ultra-short cages under half an inch to longer options up to 5 inches, and ring diameters ranging from 36mm to 55mm, there’s definitely something for everyone.

Tools You’ll Need (quick list)

• Soft tailor’s tape (or string + ruler)
• Mirror and neutral-temperature room
• Notepad (or notes app) to log 3 readings and averages
• Optional: non-stretchy string for circumference, caliper for diameter checks

Pro Tip: Always measure in a room with a neutral temperature - cold or heat can affect your size and throw off your measurements.

How To Measure Chastity Cage Length Accurately

So how long is too long and how short is too short? You want a chastity cage which fits snuggly. A cage longer than your flaccid penis lets you expand when semi-erect. We think being able to get any erection does not fit the purpose of male chastity.

The male penis is soft and flexible when flaccid. You can use a smaller cage than the flaccid length. But we advise not to compress too much. Too much pressure can block blood flow. You will know you have the perfect length when the tip of your penis in a flaccid state is touching the end of your chastity cage without pressing heavily against it.

For that same reason, to measure your cage, you must ensure that you are in this state without being aroused. This can be difficult but please take the time to allow any erection to subside and look for the most natural state possible before taking a measurement.

If you have a measuring tape, excellent, this will be slightly better than using a straight ruler but if a ruler is all you have at hand then don't panic, we can still get good measurements. Start measuring from your pubic bone, running along the top of your penis to the tip. Take a few different measurements during the day and aggregate them together as there will be natural variations.

When you have this measurement, it is common practice to subtract 1 quarter of an inch when you start looking at cages. We want that fit to be snug, and we want the tip of your penis pressing slightly against the tube of the cage. And with that final measurement, penis length when flaccid minus 1/4 inch, you are ready to look at the lengths of chastity cages in the store.

Measuring The Chastity Cage Ring

Fitting the ring around the testicles is the hardest part. We want the ring to hold your cage in place and grip your body. It should be comfortable and not block blood flow or your ability to use the bathroom.

It's a common misconception that a tight ring will cause friction with the body as you wear it each day. We tend to observe that a snug fitting ring will actually cause less friction on the body as it simply moves less. Although loose, a ring that is too large will constantly move back and forth and irritate the skin.

To measure the distance around the base of your testicles, you will need that measuring tape again or if you do not have that, a piece of string which you can mark then measure against a ruler.

Once more ensure that you are in a room where the temperature has been fairly neutral for some time and remove clothes to allow your body to equalise with the ambient temperature for a few minutes first.

Take your penis and testicles in one hand, think about clasping them all within your hand and gently pulling them away from the body to expose the line you are going to measure around. Take your string or tape and run it around from the pubic bone at the top all the way under and back to meet at the top.

Mark your string with a pen when it crosses over and if you are using a tape then note the measurement as it crosses over the starting point. Once more, repeat this process a couple more times throughout the day and average out that measurement.

Now comes time for a little maths to get the ring diameter. The measurement you have recorded is the circumference. So that's in essence a circle and we want to know the diameter - the distance from one side to the other in a straight line. To find this we need to divide by 3.14 (pi) and that's the magic number.

For example, let's say you average out a measurement of 159mm. Divide that by 3.14 and you will get a measurement of 50.5mm. Based on that, the ring size that is best going to suit you is the 50mm ring, often known as 'large'.

Pro tip: Don’t oversize the ring. Loose rings chafe more because they move more.

Know Your Chastity Ring Types

There are two shapes you will see recurring often in the world of chastity. Circular and arced rings. Both sizes are comparable, the sizing doesn't change much based on shape, but feel a little different on the body.

Circular rings are the classic shape that most of the original chastity cage designs utilised. A uniform circle, very easy to measure for and it's hard to go wrong.

Arc rings are a little longer from top to bottom than circular rings. They get narrower as they go down. This changes how they press against the testicles but gives a similar result.

A 40mm circular ring is the same size as a 40mm arc ring. It is best to try cages of each type to see what you like. Your measurements work for both types.

The most common sizes you will encounter are 40mm, 45mm and 50mm. These are also know as small, medium and large rings. In some cases, cages will be compatible with sizes outside of that spectrum, including a 36mm, extra small ring, and a 55mm, extra large ring. These cater to people who fall outside of the mean range of sizes but options are just a little more limited in these sizes.

Measuring For The Internal Cage Diameter

Now that you are reacquainted with pi calculations, we will be repeating that once more, this time for the shaft of your penis. Again ensure a relaxed state in a room that is not too cold and not too warm. Using a measuring tape or string, wrap it around your penis and note where the measurement crosses over on your tape, or mark a string with a pen then measure it against a ruler.

Repeat this process a further 2-3 times throughout the day and average out the measurement before dividing by 3.14 to give you the flaccid diameter of your penis.

As a reminder, we are looking for a snug fit. Keep in mind that your penis will squeeze into an area slightly smaller with no discomfort so do not worry about that. Our goal here is to stop any erection dead in its tracks.

Measuring The Gap Between Cage And Ring

This is an often overlooked part of the chastity fitting process and addresses the gap that exists between the closed cage, once it has been locked shut, and the ring that it is affixed to. It is through this gap that your testicles will sit. The role of this gap is to clasp your ball sack to prevent escape. Narrow enough to not allow a gap for your testicles to slip through, and wide enough that it's not squashing the skin of your testicles uncomfortably.

Some people find the challenge here is down to how tightly their testicles sit against their body. Some people feel discomfort at first because their testicles try to pull back. The chastity cage stops this movement. Others find their testicles sit comfortably below the ring from the start.

For everyone though, your body will adjust over the first week of wear and things that perhaps initially feel uncomfortable will settle as you get used to wearing the cage. By the second week most people will almost forget that they are wearing it.

Other Considerations

Color

Chastity cages occasionally offer you the opportunity to get a little creative on the color front. Steep cages are usually silver. Sometimes special editions come out. These let you get a steel cage in black or gold.

More typical colours are available on silicone and resin cages, with blue, black, clear, and pink being common to see. For those who include an element of feminisation in their chastity play, pink is a popular choice. Our tip, give it a try, it's a lot more popular than you might think!

Lock

The locks on chastity cages will either be internal or external. An external lock looks like a good old fashion padlock. Typically there will be a small loop built into the top of the cage where the ring and cage connect and a lock will loop through there before being closed. Such a lock provides an interesting look to the cage, especially for a key holder but keep in mind when your cage is steel, the movement of the lock will create a little noise as you move!

An internal lock forms a small tube between the ring and cage when they are connected. A lock piece is then inserted into that newly formed tube and turned with the key ensuring it cannot come out and the cage cannot open. This internal lock has become widespread in recent years and you will see it on most of our cages here in the store.

Material Snapshot Table

Silicone, resin or steel. Roughly speaking that is the material choices for your chastity cage. Each has their own advantage, whether it be practical or an aesthetic choice.

Silicone cages are typically soft and lightweight and therefore quite malleable under clothing. They also often come in a wide variety of colours giving you some interesting aesthetic choices. Great for a beginner who is perhaps a little daunted about undertaking their journey of male chastity.

Resin cages are made of a high-quality material. They feel hard like plastic but are almost as strong as steel. They keep their shape and do not bend. They give the security of steel but feel light like silicone. Unsurprisingly this is a popular choice for many.

Stainless steel chastity cages are perceived as the top tier of chastity cages. Often this is more symbolic than anything but one cannot deny the allure of a beautifully crafted steel cage locked firmly onto their partners' prized parts. Chastity looks firm and unmovable. It does not bend or flex.

Caption: At-a-glance material comparison for comfort, security, and wear style.

Quick Reference Tables (Size Cheat Sheets)

Use these quick-reference tables to translate your raw measurements into practical sizing decisions.

Measurement Checklist

Caption: Quick measurement checklist: what to record, how to measure, and how to pick your final size.

Ring Circumference → Ring Size (cheat sheet)

Caption: Chastity Ring Sizing Made Simple - Find your ideal ring size by matching your measured base circumference to the closest standard size.

How to Measure for a Cock Cage: Key Things to Keep in Mind

If you’ve ever wondered how to measure for a cock cage, the steps are simple and very similar to measuring for any chastity cage. The key is accuracy and patience, measuring when flaccid, using a soft ruler, and following each step to match your anatomy. Whether you’re using “cock cage” or “chastity cage,” the goal is the same: finding the perfect fit that’s secure, breathable, and wear-all-day ready.

Ready to find your perfect fit?

Don’t settle for guesswork, get the cage that guarantees comfort, security, and peace of mind. Browse our expert-recommended chastity cages now and experience a snug, safe fit from day one!

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