Chastity Cage Size Calculator
The Lockd Chastity Cage Size Calculator turns three quick measurements into a recommended cage length, internal diameter, and base ring size in under a minute, then shows you cages that actually match. Nothing you enter is stored or sent anywhere. Use the tool below, then read on for measuring tips and answers to common fit questions.
Getting the size right is the difference between a cage you forget you are wearing and one that ends up in a drawer. The Lockd chastity cage size calculator takes three quick measurements and turns them into a recommended cage length, internal diameter, and base ring size, using the same sizing logic experienced wearers rely on. It takes under a minute, and nothing you enter is stored or sent anywhere.
Chastity Cage Size Calculator
Enter your three measurements while fully flaccid and get your recommended starting size instantly.
Top of the shaft, from body to tip. Measure two or three times and use the smallest reading.
Circumference around the thickest part of the shaft, snug but not compressing.
Around everything at the base, behind the testicles and over the shaft. This one matters most, so take it twice.
Cages in your size
Your measurements never leave your browser.
How the Calculator Works
Lockd built this calculator around three simple rules of thumb used across the chastity community. Cage length is your flaccid length minus roughly half an inch, because a snug cage prevents chafing and pull-out. Internal diameter is your flaccid girth divided by pi, converting circumference into the tube width you actually need. Ring size is your base circumference divided by pi, minus a few millimetres so the ring holds securely without pinching. The calculator does the math and rounds to the sizes you will actually find on product pages.
Back to top āHow to Take Your Measurements
1. Flaccid length
Measure along the top of the shaft, from where it meets your body to the tip, pressing lightly against the pubic bone. Size fluctuates through the day, so measure two or three times and use the smallest number. Never measure right after a shower, exercise, or arousal.
2. Flaccid girth
Wrap a soft tape around the thickest part of the shaft while fully flaccid. It should sit against the skin without compressing it. No tape? Use string, mark it, and measure against a ruler.
3. Base ring circumference
This is the measurement that matters most. Loop string around everything at the base, behind the testicles and over the top of the shaft, exactly where the base ring will sit. Snug but comfortable. Take it twice and average the results.
Back to top āGetting the Fit Right
If you land between sizes, go shorter on the cage. Extra length invites chafing and makes pull-out easier, while a snug tube stays put and stays comfortable. For the ring, let comfort decide: it should rotate freely with no pinching.
For a deeper walkthrough of fit troubleshooting, read the full Lockd chastity cage sizing guide, or the dedicated guide to ring sizes if the base ring is what is giving you trouble.
Material affects fit too. Rigid steel tubes need more precision than flexible options, so if your measurements sit at the edge of a size, a softer device is more forgiving. Browse the Lockd range of silicone chastity cages if flexibility is the smarter choice for you. Once you have your numbers, every device in the Lockd range lists all three dimensions, so you can browse all chastity cages and match your results directly to a product page.
Back to top āFrequently Asked Questions
How accurate is the chastity cage size calculator?
The Lockd calculator gives a reliable starting point based on sizing rules used widely in the chastity community. Anatomy varies, so treat the result as your first fitting, wear the device for short sessions, and adjust ring or cage size based on comfort.
Should I measure flaccid or erect?
Always flaccid. Chastity cages are sized for your flaccid state, since that is how you will wear the device. Measuring erect leads to a cage that is far too large to be secure or comfortable.
What should I do if I am between sizes?
Choose the shorter cage length, since a snug tube prevents chafing and pull-out. For the base ring, prioritize comfort: if a smaller ring pinches or causes numbness, size up. The Lockd ring size guide covers between-size decisions in more detail.
How tight should the base ring be?
Snug enough that the device does not slide off and loose enough to rotate freely on the skin. Any tingling, coldness, or color change means it is too tight. Remove the device immediately and move up a ring size.
Does the material change the size I need?
The measurements stay the same, but rigid materials like stainless steel are less forgiving of borderline sizing than silicone or flexible resin. If your numbers fall between sizes, a flexible device gives you more margin for error.
Can I use these measurements for any brand of cage?
Yes. Cage length, internal diameter, and ring diameter are universal dimensions, and every device sold by Lockd lists all three. Note that some brands measure ring size as diameter and others as circumference, so check which one a product page uses before ordering.
About This Calculator
This free chastity cage size calculator is built and maintained by Lockd, an adult lifestyle brand specializing in male chastity devices. Lockd publishes sizing resources, fit guides, and product education to help wearers at every experience level find a device that is secure, comfortable, and safe for long-term wear. Your measurements never leave your browser.
Back to top ā
About the Author ā Shoana Miller, Lockd Editorial Team
Shoana Miller is a certified sex educator and BDSM lifestyle coach with over 10 years of experience in sexual wellness and intimate product reviews. Holding a Master's in Human Sexuality, she has contributed to leading publications on chastity play, power dynamics, and relationship enhancement. Follow her on LinkedIn.
