Chastity Cage Size Guide
Quick answer: measure around the base of your penis and testicles while relaxed, divide by 3.14 to get your ring diameter, and pick the nearest ring size. Then measure your soft length and choose a cage the same length or slightly shorter. If you're between sizes, go one size up.
A chastity cage only works if it fits. Too tight and it pinches within hours; too loose and it slides off in your sleep. The good news is that you only need a piece of string, a ruler and five minutes. Here's exactly how we'd measure.
What you're measuring
Every chastity cage has two parts, and each one needs its own measurement:
- The base ring sits behind your testicles, around the base of your penis. Its size is the diameter of that ring, usually shown in millimetres (for example 40mm or 45mm).
- The cage sits over your shaft. Its size is the internal length, and on our site you'll see this as Nano, Nub, Small or Large, with exact dimensions on each product page.
Step 1: Get relaxed
Measure when you're fully soft, warm and relaxed. A warm shower beforehand helps. Measuring when cold gives a reading that's too small; measuring when aroused gives one that's far too big. Either way, you'll end up with the wrong cage.
Step 2: Measure your ring size
- Wrap a piece of string or a strip of fabric around the base of your penis and behind your testicles, where the ring will sit.
- Pull it snug but not tight. You should be able to slide a finger underneath.
- Mark where the string meets, then lay it flat against a ruler. That's your circumference.
- Divide your circumference by 3.14. That's the ring diameter you need.
| Your circumference | Ring diameter to choose |
|---|---|
| Up to 12.8cm | 40mm |
| 12.9cm to 13.6cm | 42mm |
| 13.7cm to 14.6cm | 45mm |
| 14.7cm to 15.4cm | 48mm |
| 15.5cm to 16.0cm | 50mm |
| 16.1cm and above | 52mm |
Ring sizes vary by cage, so check which sizes the product you like comes in. If your measurement falls between two sizes, choose the larger one.
Step 3: Measure your cage length
While still soft, measure along the top of your penis from the base to the tip. Then choose:
- The same length for comfortable, long-term wear. Best for beginners.
- Slightly shorter for more restriction, once you're used to wearing a cage.
Never choose a cage that's longer than your soft length, or you'll be able to slip out.
Step 4: Choose your style
| Material | Good for | Worth knowing |
|---|---|---|
| Resin | Lightweight all-day wear and first-timers | Check edges for rough spots before wearing |
| Steel | Security and easy cleaning | Heavier, so ring fit matters most |
| Silicone | Flexible, forgiving comfort | Less secure than resin or steel |
Not sure where to start? Our Black Resin Hive Chastity Cage is light enough to forget you're wearing it, and comes in Nano, Nub and Small. For steel, try the Birdcage or the heavier-duty Lockup Steel Chastity Cage, both in 40mm and 45mm.
Step 5: Check the fit
Once it's on, a good fit feels secure but not tight. Wear it for an hour or two the first time and check:
- Good signs: no pinching, normal skin colour, and the cage stays in place when you move.
- Too tight: swelling, numbness, tingling, cold skin or skin turning dark or blue. Take it off straight away and size up.
- Too loose: you can pull out, or the cage slides forward. Size down on the ring.
If the cage pulls away from your body, a Chastity Cage Security Belt takes some of the weight and holds it steady. One customer put it simply:
"The straps did an amazing job supporting the chastity ring and held it in place."
Verified buyer, Chastity Cage Security Belt
Delivery
Orders placed before 2pm, Monday to Friday, are dispatched the same day by Royal Mail Tracked 48, in plain, discreet packaging. Your bank statement will show CCSUK.
Frequently asked questions
What size chastity cage ring do I need?
Measure around the base of your penis and testicles while relaxed, then divide by 3.14. A 14cm circumference, for example, means a 45mm ring.
Should I size up or down if I'm between sizes?
Size up on the ring for comfort. A ring that's slightly loose is safer than one that's too tight.
How long should my chastity cage be?
The same as your soft length for comfort, or slightly shorter for extra restriction. Never longer.
Can I wear a chastity cage overnight?
Yes, once you're sure of the fit. Start with a few hours during the day, and take it off straight away if you notice swelling, numbness or colour changes.
What's the difference between Nano, Nub, Small and Large?
They describe the cage length, from shortest (Nano) to longest (Large). Exact measurements are listed on each product page.
This guide is general information, not medical advice. If you have any discomfort that doesn't settle, speak to a GP or sexual health clinic.