Find your size

Use soft measuring tape, or string and a ruler. Measure fully soft from the body junction along the top curve to the tip of the head. Let it hang naturally without pulling or supporting it. Leave foreskin in its normal position, but don’t include skin extending beyond the head.

Take at least six readings at different times over a day or two. Avoid unusually cold conditions and readings immediately after a hot bath. Enter at least six normal readings above. Extra readings are optional.

We sort your readings and average the lowest third, using at least two readings. If the smallest is more than 12.7 mm below the next, we exclude it. This follows the estimator in KINK3D’s current calculator, with two safeguards: we keep the exact measurement when matching a size, and we don’t force measurements outside the supported range into the smallest or largest cage.

Near a size boundary, the result offers the neighbouring size for comparison. At an exact boundary we suggest the shorter size, following KINK3D’s written guide. The suggested size describes a fit range; it is not the cage’s physical length.

The manufacturer also publishes rounded centimetre ranges. To prevent a unit switch changing your result, this tool uses exact inch-to-millimetre boundaries. Baby’s published centimetre guide begins at 3 cm; results from 3–3.175 cm need particular care because of that rounding difference.

A measurement around your body cannot reliably determine a base-ring size. If you have a comfortable KINK3D ring, use its number and style. A comfortable flat, circular ring from another brand can be compared by its inside diameter, but its fit is only an estimate.

If you have no known fit, this tool leaves your ring unconfirmed. KINK3D identifies #2 Standard (44.5 mm) and #3 Standard (47.6 mm) as common first choices. You can deliberately select one as a trial, but neither is calculated from your body measurements. Trying rings or getting fitting advice provides more certainty before buying online.

Ring style changes the cage-to-ring gap. The result checks the manufacturer’s table for your exact cage and ring combination. There is no universal gap measurement that confirms comfort or safe fit. We show the exact published gap without treating it as a pass/fail test.

Standard is the usual first choice. A very thin shaft when soft, or previous cages feeling consistently loose, can suggest Narrow; very thick or consistently tight can suggest Wide. This is a starting suggestion rather than a body-width calculation. Each size has different dimensions and not every width is made in every size.

Cobra has a tapered head ring. Viper has a more uniform internal width. Neither a length match nor your previous cage’s width proves the new design will fit. The result includes the exact published dimensions for comparison.

Review the selected options, price and availability in the builder. The handoff selects a full kit with cage, ring, lock and keys. No item is added automatically.

Start with short fit checks. Stop use if you notice restricted circulation, bruising or irritation. A calculator cannot confirm comfort or safe fit. If the result needs a fit check, ask for advice before ordering.

Your body measurements stay in this page’s memory. They are not placed in the builder link or saved by this calculator. The builder link contains product choices only.