Choosing the right dildo is about more than selecting the longest or largest option. Total length, insertable length, diameter, circumference, shape, firmness and intended use can all affect how a product feels.
This guide explains the measurements used on RealDildos product pages and helps you compare different sizes more confidently.
Understanding Product Measurements
Before comparing products, it is important to understand what each measurement means.
| Measurement | What It Means | Why It Matters |
|---|---|---|
| Total Length | The complete length from the tip to the bottom of the product | Useful for storage and understanding the overall scale |
| Insertable Length | The portion that may be inserted, excluding the base, handle or external components | More useful than total length when comparing usable length |
| Diameter | The width measured straight across the product | Helps indicate how narrow or wide the product is |
| Circumference / Girth | The distance measured around the product | Often gives a better sense of perceived fullness |
| Widest Point | The largest diameter or circumference on a shaped or tapered product | Important for products that are not the same width throughout |
| Base Width | The width of the suction cup, stand or flared base | Helps determine stability and suitability for hands-free use |
| Weight | The total weight of the product | Larger or denser products may require more support and control |
Measurements may vary slightly between production batches. Always review the specifications on the individual product page before ordering.
Total Length vs. Insertable Length
Total length and insertable length are not the same.
A product may have a total length of 8 inches but an insertable length of only 6 inches because part of the product is used for the base, handle, motor or suction cup.
When comparing products for fit, focus primarily on the insertable length. Total length is still useful for understanding the overall scale and how easy the product may be to hold or store.
You never need to use the entire insertable length. Comfort and control are more important than reaching a particular depth.
Length Reference Guide
The following categories are general shopping references, not medical or universal fit standards. Individual comfort varies.
| Insertable Length | Approximate Metric Size | General Description |
|---|---|---|
| Under 5 in | Under 12.7 cm | Compact |
| 5–6.5 in | 12.7–16.5 cm | Moderate length |
| 6.5–8 in | 16.5–20.3 cm | Long |
| 8–10 in | 20.3–25.4 cm | Extra long |
| Over 10 in | Over 25.4 cm | Oversized or specialty length |
A longer product does not require full insertion. Some customers choose a longer design because it provides additional grip or flexibility rather than because they intend to use the full length.
Shape also matters. A curved, tapered or textured product may feel different from a straight product with the same insertable length.
Diameter vs. Circumference
Diameter is measured straight across the product. Circumference, also called girth, is measured all the way around it.
The formulas are:
Circumference = Diameter × 3.14
Diameter = Circumference ÷ 3.14
For example, a product with a diameter of 1.5 inches has an approximate circumference of 4.71 inches.
Diameter and Circumference Conversion Table
| Diameter | Approximate Circumference | Diameter in Centimeters | General Profile |
|---|---|---|---|
| 1.00 in | 3.14 in | 2.54 cm | Slim |
| 1.25 in | 3.93 in | 3.18 cm | Slim to moderate |
| 1.50 in | 4.71 in | 3.81 cm | Moderate |
| 1.75 in | 5.50 in | 4.45 cm | Full |
| 2.00 in | 6.28 in | 5.08 cm | Extra full |
| 2.25 in | 7.07 in | 5.72 cm | Oversized |
| 2.50 in | 7.85 in | 6.35 cm | Specialty oversized |
| 3.00 in | 9.42 in | 7.62 cm | Extreme oversized |
These descriptions are intended only to help compare products. They do not guarantee comfort or suitability for every person.
For tapered or irregularly shaped products, check whether the listed diameter refers to the shaft, head, knot, widest point or base.
Inch and Centimeter Conversion
RealDildos product pages may display measurements in inches, centimeters or both.
| Inches | Centimeters |
|---|---|
| 1 in | 2.54 cm |
| 5 in | 12.70 cm |
| 6 in | 15.24 cm |
| 7 in | 17.78 cm |
| 8 in | 20.32 cm |
| 9 in | 22.86 cm |
| 10 in | 25.40 cm |
| 12 in | 30.48 cm |
To convert inches to centimeters:
Inches × 2.54 = Centimeters
To convert centimeters to inches:
Centimeters ÷ 2.54 = Inches
How to Measure a Product
For the most accurate comparison, use a rigid ruler for length and a flexible measuring tape for circumference.
Measuring Length
Measure from the tip to the point where the usable shaft meets the base. Do not include a suction cup, handle, control unit or decorative base when measuring insertable length.
Measuring Diameter
Measure straight across the shaft at the point you want to compare. For products with changing thickness, measure the narrowest section, main shaft and widest point separately.
Measuring Circumference
Wrap a flexible measuring tape around the shaft without pulling it tightly. If you do not have a flexible tape, wrap a piece of string around the product, mark where the ends meet, and then measure the string with a ruler.
What Affects Perceived Size?
Two products with identical measurements can feel noticeably different. Consider the following factors.
Shape
A tapered shape gradually increases in width and may feel different from a product with the same thickness from tip to base.
A pronounced head, knot, ridge or textured surface can make a product feel fuller than its basic shaft measurement suggests.
Firmness
A firmer product generally maintains its shape and may feel more substantial. A softer product can compress and flex, which may make the same measured diameter feel different.
Firmness descriptions are not standardized across all brands. Terms such as soft, medium and firm may vary by manufacturer.
Texture
Raised veins, ribs, bumps and other textures can increase sensation even when the product has a moderate diameter.
Curvature
Curved products may create more targeted pressure. The curve can also affect the usable depth and how the product is positioned.
Weight
Large or dense products may require more control and support. Check the listed weight, especially when considering an oversized, glass or metal design.
Base Design
A wide suction cup or flared base adds to the total size but not necessarily to the insertable length. It may also provide additional grip or support for hands-free use.
Choosing a Size
There is no single correct size for everyone. Personal preference, experience, intended use, shape and firmness all matter.
If You Prefer Easier Control
Consider a product with:
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A moderate insertable length
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A slimmer or tapered profile
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A clearly defined handle or base
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A softer or more flexible shaft
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A smooth surface
If You Prefer More Fullness
Focus on diameter or circumference rather than length alone. A wider product with moderate length may provide more fullness than a long, narrow design.
Review the measurement at the widest insertable point, especially for products with large heads, knots or changing shaft thickness.
If You Prefer More Depth
Compare insertable length rather than total length. A longer design with a large decorative base may offer less usable length than expected.
Choose a design that remains easy to hold and control. Additional length does not mean that the entire product must be inserted.
If You Are Considering an Oversized Product
Do not rely only on product photos. Carefully review:
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Insertable length
-
Maximum diameter
-
Maximum circumference
-
Shape of the widest point
-
Firmness
-
Product weight
-
Base size
Moving directly from a moderate size to an extreme size may be uncomfortable. A gradual progression provides a more practical way to understand personal preferences.
Choosing a Size for Anal Use
Only use products designed for anal use and equipped with a secure flared base or another feature that prevents the product from being drawn fully inside the body.
The base should be noticeably wider than the widest insertable part of the product. A suction cup alone should not automatically be treated as a substitute for a properly designed flared base.
For easier control, consider a tapered shape, moderate length and smaller starting diameter. Use sufficient compatible lubricant and proceed gradually. Stop immediately if you experience sharp pain, persistent discomfort, numbness or bleeding.
Choosing a Size for Hands-Free Use
For hands-free use, check the base width and surface requirements in addition to shaft measurements.
A wider suction cup may provide more stability, but performance depends on the surface. Suction cups generally work best on smooth, clean, nonporous surfaces such as glass or tile.
Large or heavy products may place more pressure on the base and may require additional support.
Material and Lubricant Compatibility
The appropriate lubricant depends on the product material. Water-based lubricant is generally compatible with a wide range of materials, but always check the product or manufacturer instructions.
Some lubricants may affect certain materials. Test compatibility carefully when the product information is unclear.
Use enough lubricant to reduce friction and reapply when necessary. Discontinue use if the product causes persistent discomfort or irritation.
Before Using a New Product
Before first use:
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Confirm that the product matches the ordered size, color and material.
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Inspect the surface for cracks, tears, peeling, sharp edges or exposed internal parts.
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Clean the product according to its care instructions.
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Read any instructions supplied by the manufacturer.
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Begin slowly and remain within your personal comfort level.
Do not use a product that appears damaged or defective.
Cleaning and Storage
Clean products before and after use according to the material and manufacturer instructions. Allow the product to dry completely before storage.
Store products separately in a clean, dry location away from direct sunlight, excessive heat and sharp objects. Some soft materials may react when stored in direct contact with each other.
When sharing a product, clean it between users and use a new compatible barrier when appropriate.
Important Safety Reminder
Size categories are approximate shopping references and are not medical recommendations. Comfort differs from person to person, and no size is suitable for everyone.
Do not force insertion or continue through sharp pain. Stop using a product if you experience persistent pain, numbness, bleeding, irritation or another unexpected reaction. Seek advice from a qualified healthcare professional if symptoms persist or if you have a health condition that may affect product use.
Still Unsure Which Size to Choose?
Compare the insertable length, maximum diameter, circumference, firmness and shape listed on each product page.
If a measurement is missing or unclear, contact us before ordering:
Please include the product link or product name so our customer service team can help you check the available specifications.
