How to compare realistic dildo dimensions
Separate the size label, overall length, insertable length and shaft diameter.
Start with the measurements you can compare
The King Cock tan model is labeled 10 inches. Its listing gives 10.39 inches overall and 9.49 inches insertable. The Master Series set is labeled 9 inches, with 10.1 inches overall and 7.1 inches insertable. Those examples show how much the label can differ from the usable length.
Check the exact color and size selection before using the numbers. If the listing groups several variants and prints just one set of measurements, confirm which option the numbers refer to.
Keep diameter and circumference separate
Diameter runs across the shaft. Circumference, often called girth, runs all the way around. If the listing gives both, use the actual figures. For a curved or irregular shape, a value calculated from circumference only approximates a round cross-section.
A tapered shaft may have different diameters at different points. A maximum width is useful when comparing fit, but only if the listing identifies it as the widest part of the shaft. The base, package and included rings have their own measurements.