Sissy Chastity Sizing Guide: How to Measure for the Perfect Fit

Correct sizing is the difference between a comfortable, wearable experience and painful frustration. This technical guide walks you through the precise measurements needed for a properly fitting chastity device.

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Why Sizing Matters

Poor sizing is the number one reason people abandon chastity practice. A device that doesn't fit properly causes:

• Too Tight: Circulation problems, numbness, skin damage, pain during erections
• Too Loose: Chafing from movement, "pullout" escapes defeating security, skin getting pinched
• Wrong Gap: Testicle escape or painful pinching of scrotal skin

Taking accurate measurements and understanding what each measurement means will save you money (no wasted purchases) and ensure a safe, wearable device.

The Three Critical Measurements

1. Flaccid Penis Length → Determines Cage Length

This measurement determines how long your cage tube should be. For sissy chastity, many prefer shorter "nub" or "nano" sizes for aesthetic reasons, but safety must come first.

How to Measure

1. Measure when completely flaccid—not semi-erect. Morning is not ideal; measure later in the day.
2. Use a rigid ruler, not a tape measure
3. Place the ruler on top of your penis, pressing the end firmly into the pubic bone (this accounts for the fat pad)
4. Measure to the tip of the glans
5. Record this measurement in millimeters

Choosing Your Cage Length

Your Flaccid Length	Recommended Cage Type	Typical Length Range
Less than 50mm	Nano/Micro	20-35mm
50-75mm	Nub/Small	35-50mm
75-100mm	Small/Medium	50-70mm
100mm+	Medium/Large	70mm+

The "Nub" Aesthetic

Many in sissy chastity prefer shorter cages than their measurements might suggest, creating a minimal, smooth appearance. This is acceptable within limits:

• The glans should not be compressed painfully
• You must be able to urinate through the opening
• There should be no persistent pressure on the glans

If you want a shorter cage than standard recommendations, start with the recommended size and gradually work down as you learn what your body can accommodate.

2. Base Ring Size → Determines Comfort and Security

The base ring is the circular band that sits behind your scrotum and around the base of your penis. This is the most critical measurement for both security and safety.

How to Measure

1. Use a soft tape measure or a piece of string
2. Wrap it around the base of your penis AND behind your scrotum—both testicles should be in front of the tape
3. Pull snug but not tight—you should be able to slip a finger underneath
4. Record this circumference measurement
5. Divide by π (3.14159) to get the diameter

Example: If your circumference is 150mm, divide by 3.14 = 47.8mm diameter ring

Common Base Ring Sizes

Circumference	Diameter	Size Category
125-135mm	40-43mm	Small
136-150mm	43-48mm	Medium
151-165mm	48-53mm	Large
166mm+	53mm+	Extra Large

The Fit Test

When trying on a base ring:

• Too Tight: You cannot comfortably fit one finger between the ring and your body. Testicles or penis become discolored. Numbness occurs.
• Too Loose: You can fit two or more fingers easily. Testicles can slip through. The ring moves around significantly.
• Just Right: You can fit one finger underneath with slight resistance. Snug but not constricting. No color change or numbness after 30 minutes.

Ring Shape

Base rings come in different shapes:

• Circular: Most common, works for most body types
• Oval: Often more comfortable as anatomy is not perfectly round
• Curved/Ergonomic: Designed to follow body contours, often the most comfortable for extended wear

3. The Gap → The Space Between Ring and Cage

The "gap" is the distance between the back of the base ring and the start of the cage tube. This affects how scrotal skin and the perineum sit when wearing the device.

Why It Matters

• Gap Too Small: Skin gets pinched between the ring and cage. Painful, especially when sitting.
• Gap Too Large: Testicles can slip through the gap and become trapped on the wrong side ("ball escape"). Also reduces security.

Finding Your Gap

Most devices have a fixed gap, but some include spacers for adjustment. General guidelines:

• Smaller testicles typically need smaller gaps (around 10-15mm)
• Larger testicles need larger gaps (15-25mm)
• If you experience pinching, try a larger gap
• If testicles escape, try a smaller gap or a different ring size

The Test Fitting Process

Before committing to a device, follow this process:

Step 1: Ring Only (30 minutes)

1. Wear just the base ring for 30 minutes
2. Check for color changes, numbness, or pain
3. Sit, stand, and walk around
4. If problems occur, you need a larger ring

Step 2: Full Device, Unlocked (1 hour)

1. Assemble the full device without locking
2. Wear for one hour during normal activities
3. Note any pinching, pressure points, or discomfort
4. Remove easily at any sign of problems

Step 3: Full Device, Locked (2-4 hours)

1. Lock the device with easy key access
2. Extend to 2-4 hours including sitting and walking
3. Urinate at least once to test the opening placement
4. Monitor for any cumulative discomfort

Step 4: Daytime Wear (8+ hours)

1. Wear through a normal day—work, activities, etc.
2. If successful, you've confirmed your sizing
3. Proceed to overnight attempts

Common Sizing Mistakes

Measuring While Erect or Semi-Erect

Problem: Leads to choosing a cage that's too long for daily wear. The cage should fit your flaccid size; erections are supposed to be restricted.

Solution: Always measure when completely flaccid. Wait at least 30 minutes after any arousal.

Choosing Style Over Fit

Problem: Selecting a tiny "nub" cage because it looks appealing, even though it doesn't fit your anatomy.

Solution: Start with properly sized devices. Work down to smaller sizes gradually as you learn what your body tolerates.

Ignoring Ring Size Entirely

Problem: Focusing only on cage length. The ring is actually more important for safety and security.

Solution: Measure your ring size carefully. Many devices offer multiple ring sizes—use the correct one.

Not Accounting for Temperature

Problem: Measuring in a cold room when genitals are retracted, then having circulation problems when warm.

Solution: Measure at room temperature when relaxed. Body size varies—choose a ring that works in all conditions.

Adjusting for Different Device Types

Cage-Style Devices

Traditional tube cages. Size according to the measurements above. Consider:

• Ventilation slots affect fit—more open designs may feel less restrictive
• Material affects perceived tightness—metal feels more rigid than silicone

Flat/Inverted Designs

Some cages push the penis flat or inverted rather than extending it. These require:

• Accurate glans width measurement
• Shorter length than standard recommendations
• Often a snugger ring to prevent pullout

Integrated Designs

Devices where the ring and cage are one piece. Less adjustability means:

• You must know your size precisely before purchasing
• Returns/exchanges may not be possible for hygiene reasons
• Measure multiple times and consider starting with an adjustable device

When to Size Up vs. Size Down

Consider a Larger Ring If:

• You experience any discoloration
• Numbness occurs, even briefly
• The ring leaves deep, lasting marks
• Swelling appears behind the ring

Consider a Smaller Ring If:

• Testicles frequently escape
• The device moves around excessively
• You can pull out easily (though some pullout is normal with most devices)

Consider a Longer Cage If:

• Your glans is constantly compressed against the end
• Urinating is difficult due to blocked opening
• You experience significant pain during erection attempts

Consider a Shorter Cage If:

• There's significant empty space at the end
• The cage moves back and forth on your penis
• You want a more minimal aesthetic (and current size is safe)

Printable Sizing Tools

Many device manufacturers offer printable sizing guides—rings of various diameters that you can cut out and test. These are helpful but not a replacement for actual device fitting.

When using printable guides:

• Print at 100% scale—do not "fit to page"
• Verify the scale by measuring printed dimensions
• Paper rings are thinner than actual rings—go slightly larger
• Test with the paper ring for extended periods before ordering

Summary: Your Sizing Checklist

Measurement	How to Measure	What It Determines
Flaccid Length	Ruler from pubic bone to glans tip, flaccid	Cage tube length
Base Circumference	Tape measure around penis base and behind scrotum	Ring diameter (divide by 3.14)
Gap Assessment	Trial and observation during test fitting	Spacer selection

The Golden Rule: When in doubt, go slightly larger. You can always adjust down, but circulation problems from a too-tight device are immediate and dangerous.

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Related Guides

• Safety Protocol — What happens when sizing goes wrong
• Hygiene Guide — Keeping clean regardless of size
• Materials Guide — How material affects fit and feel