I see endless chastity forum posts every week about chastity device fitting problems, so I have created this quick start measuring for a chastity device guide.
Poorly Fitted Chastity Device Complaints
The two most common complaints I see about poorly fitting chastity devices concern the base ring. The first is the ring causes wearers discomfort or pain all the time. The other is that when the wearer’s penis attempts to become erect, the base ring behind the balls slides up and “chokes” the testicles causing discomfort or pain. Getting accurate measurements before buying a chastity device will usually help you avoid both issues.
In the past, I’ve always pointed guys to the measuring guide on the Mature Metal website. But recently, I discovered they changed it. I expect they were trying to improve it, but I think the guide is now less clear and less useful. That’s why I have created this measuring guide. It will work for most ball-trap devices.
I’ve aimed the guide at those who plan to order a custom-made device. However, taking proper measurements before buying an off the shelf device is never a waste of time. Many manufacturers are now providing at least some basic measurements you can use to choose a better fitting cage or tube.
The three measurements you need are flaccid penis length, circumference of the soft penis shaft, and the circumference of an imaginary circle running around the base of your penis behind your balls.
How to Measure Penis Length
Always measure when your penis is flaccid, soft, but not “shriveled.” Penises regularly shrink and expand in length while flaccid. That is amply illustrated by the image below that I found on Wikipedia.
As the image shows, there is a wide variance in the length of the same penis photographed at six different times.
The imaged labeled 1 depicts a semi-erect penis. In image 2, the penis is returning to its normal flaccid state. Based on my experiences, image 3 depicts a flaccid penis. That’s what I most often see when I look at my penis inside a chastity cage.
The penis starts in image 4, moving toward a “shriveled” state. The state of the penis in image 3, I believe, is the flaccid length most useful for chastity device measurements.
If you measured your penis length in the state depicted in image 2, you would probably find that most of the time the tip of the penis would not touch the end of the cage or tube.
To get the most accurate measurements for a chastity device, take measurements at different times of day over two or three days. Then use the shortest measurement you obtained.
Some chastity device manufacturers like Mature Metal ask you to measure the underneath side of your penis from your balls to the tip. Others ask you to measure from the top from base to tip. Make sure to follow the appropriate instructions as that is how the manufacturer accounts for the gap between the cage and base ring. If you can’t find on their website which measurement a manufacturer uses, call or email and find out.
Whether you measure from the bottom or top, a ruler is the best device for measuring length. If you measure the underneath side of your penis, take care not to press the end of the ruler into your scrotum. The ruler should only lightly touch the skin.
Always record your measurements. Don’t rely on memory.
After taking several penis length measurements at different times of day over several days, choose the smallest measurement. You should then subtract a small amount.
Mature Metal suggests subtracting 1/4-inch. That’s what I did when I ordered my first Mature Metal cage. As it turned out, the cage is about 1/2-inch too long, and the tip of my penis rarely touches the end.
That wasn’t the fault of Mature Metal. They built what I asked for. And I feel sure I took accurate measurements. So that told me subtracting 1/4-inch is not enough. Since the cage was about 1/2-inch too long, I now subtract 3/4-inch from my smallest length measurement when ordering custom-made cages. I recommend never subtracting less than 1/2-inch.
You can’t really go too short. You can easily compress your soft penis. If you push your flaccid penis toward your body, it easily compresses to half its normal length or less. If you keep pushing, it will “turtle” inside your body and disappear. The real problems with chastity cages occur when they are too long, and most guys buy devices with cages that are too long. That sets them up for attempted erection problems. More on that when we get to measuring for base rings.
Measuring Penis Circumference
The penis circumference measurement is very important for several reasons. Chastity device fabricators use this measurement to calculate the internal diameter of the cage or tube. Custom manufacturers can change the length of the cage or tube, the ring size, and the gap if needed, but they can not change the internal diameter of a cage. Whatever you order as the inside diameter, you can’t alter later.
This measurement is important because you want the cage or tube to “fit like a glove,” with your penis always touching the sides, bottom, and top of the cage or tube. Extra space inside the cage or tube will likely cause you problems during attempted erections. Erections don’t stop until your penis feels compression from the inside of the device.
If you can easily insert your flaccid penis into a cage or tube, then the interior diameter is too big. You will most often have to apply a little lubricant with a properly fitted device and work your penis into the cage or else use the “stocking method” to coax it fully into the tube.
The flaccid penis is extremely squishy. You can compress it to half or less of its normal circumference without any pain. There isn’t much risk that you’re going to strangle your penis by choosing a close-fitting cage or tube. A tip I’ve learned and use is to take your smallest penis circumference measurement and subtract 1/4-inch to get the best fit.
You don’t want the inside diameter so small that it compresses your flaccid penis, but you want a snug fit. Although soft penises are very malleable, what you don’t want is to compress your penis both in length and circumference at the same time. If you constrict the diameter too much while compressing the length any appreciable amount, you can restrict urine flow through the urethra. That’s why micro-chastity device cages only cover the glans of the penis. Those devices already compress the length of the penis to an extreme. By covering only the glans, it prevents compression of the shaft’s circumference at the same time. Urine flow through the uretha is not hampered.
I recommend using a soft tailor’s measuring tape to measure penis circumference. The measurement will be more accurate than trying to eyeball it by placing your penis on top of a ruler. You can pick up a soft tape for a dollar or two from most discount stores.
If you don’t have a tailor’s tape and don’t want to buy one, you can use the string method. Wrap a length of the string (an old shoelace works well) snugly around your penis. Then mark with a felt pen where the end of your string touches the rest of the string. Stretch out your string along a ruler and see where the felt mark is. That’s the circumference.
Base Ring Measurement
The easiest and most accurate method of measuring for a base ring is to spend $25 to buy the plastic sizing ring assortment from Mature Metal. Then you will have actual rings to try on, wear, and experiment with until you find a comfortable fit.
You will find that you can get several different sizes on. The way you can know which one is the right size is by using the fingertip test. With a properly sized base ring, you should be able to easily insert one fingertip between your skin and the inside of the ring. If you can’t, the ring is too small. If you can get two or more fingertips inside, the ring is too large.
If you don’t want to spend the twenty-five bucks, you can go old school and use either the tailor’s measuring tape or string method described in the previous section.
The thing is, the base ring size isn’t usually going to be a problem. You can get that a little off and still be fine. One of the two base ring issues I mentioned earlier—the ring rides up during an attempted erection and digs painfully into the balls—isn’t a base ring problem. It’s a cage length problem. When the cage is too long, it encourages the erection to continue. The tip of the expanding penis pushes against the end of the cage, which causes the cage to pull against the base ring. That’s always uncomfortable.
If the base ring is too small, that can be why a base ring causes constant discomfort. If the ring is too large, you may have problems with a ball popping out of the ring. Also, an oversized ring allows the device to rotate around your scrotum and penis base, which can cause friction chafing. That’s all unnecessary as the base ring measurement is probably the easiest measurement to get right, except for guys who buy the cheaper off the shelf cages where they only give you three ring size options to choose from.
Gap Measurement
The distance between the cage entrance and the base ring is called the gap. Even in the 21st Century, with all the world’s advanced technology, there is no way to measure the gap before ordering a chastity device. It remains a guesstimate subject to trial and error. But chastity device manufacturers do have some advice on the gap.
Mature Metal says ninety-percent of their customers order a 3/8-inch gap and are happy with it. Based on experience, I agree with that. I have a high and tight scrotum with average-sized balls, and 3/8-inch works for me. I once tried a 1/4-inch gap to solve a ball-popping from the base ring problem with one of my devices, but it was too close. The narrower gap caused me worse problems of its own.
If you have a loose, low rider style scrotum, a 1/4-inch gap might be a better fit. Also, guys with high and tight scrotums and larger balls might need to step up to a 1/2-inch gap to gain more comfort.
My advice is to go with the 3/8-inch gap unless there is a good reason not to. If you should find you need something different, it’s an easy fix for your device manufacturer.
Summary
Now for a quick review, and yes, this will be on the test.
- Always measure when your penis is truly flaccid, not semi-erect or shriveled.
- Take multiple measurements at different times of day over two or three days. Select the smallest measurement taken for length, circumference, and base ring.
- From your shortest penis length measurement, subtract at least 1/4-inch, although subtracting 1/2-inch will probably give you a better fit, and in my opinion, subtracting 3/4-inch an even better fit.
- From your shortest penis circumference measurement, subtract 1/4-inch.
- Best practice is to buy and use a set of sizing rings to determine base ring size. A custom-made chastity device is a big investment, and it’s worth an extra twenty-five bucks to get it right the first time. Getting the wrong size base ring and having to buy another one will usually set you back about $80.
- Go with a 3/8-inch gap unless you have a good reason to go smaller or larger.
Disclaimer: All penises are different. I’ve learned what works for me from trial and error and believe you can benefit from my experience. But your mileage may vary.