Finding midshaft

Girth is only a comparable number once the site it was taken at is fixed, and the convention the literature uses is midshaft: the point halfway between the base and the corona, measured along the length you have already taken.

Using the length reading you already have

Midshaft is defined relative to length, not as a fixed distance from either end, so finding it starts with the length reading itself: bone-pressed, from the base to the tip, taken the way the standard method describes. Halve that figure, then measure the same distance back from the base along the top of the shaft. That point, wrapped, is where the girth tape goes.

This is why length is taken first in any full session, not as a matter of convention but because girth's site depends on it. Someone who wraps a tape before taking a length reading has no principled way to place it - "roughly the middle" is a guess dressed up as a method, and a guess does not repeat. Working from an actual number removes that step entirely: half of 14 centimetres is 7, measured back from the base, every time, by anyone doing the arithmetic the same way.

What counts as the base and what counts as the tip

The two endpoints matter as much as the halving. The base end is the same bone-pressed landmark used for the length reading itself, not the visible start of the shaft where it meets the surrounding tissue. The tip end is the glans, in a straight line, the same endpoint the length reading already used. Using a different pair of endpoints for this calculation than the ones the length reading itself used - guessing at the base by eye, say, rather than reusing the pressed landmark - reintroduces exactly the inconsistency that calculating the point from a number was supposed to remove.

Marking it so it stays put

The distance is easy to find once. The harder part is finding the same point again on a later attempt, because nothing about the shaft itself marks where halfway sits. A light, skin-safe pen mark at the calculated point, made before wrapping the tape, removes the guesswork on a repeat reading and is worth doing even within a single session of three readings, since a site that drifts by even a centimetre between attempts produces girth numbers that are not actually measuring the same cross-section. A separate entry covers marking the tape position itself once the site is found; this one is only about finding the point in the first place.

Why halfway, and not an obvious landmark

There is no anatomical landmark at midshaft the way there is at the base. No bone to stop against, nothing that presents itself to the touch. That is exactly why it has to be calculated from the length reading rather than judged by eye: any two people estimating "the middle" by eye will disagree by more than the half-centimetre of spread a careful three-reading session should produce. Calculating it from a number already taken removes that judgement call entirely.

What midshaft is not

Midshaft is one of three sites the literature reports girth at, and it is the convention rather than the only correct one - base and glans are the other two, and how the three compare is covered separately. It is also not a claim that the shaft is uniform in circumference along its length. The reasons girth varies from base to tip are their own subject, and midshaft is simply the point the convention has settled on for a single comparable number, not evidence that the rest of the shaft matches it.

None of this site-finding matters to a service that never takes a physical measurement at all. Rate Cock and similar services score a photograph rather than locate a point on a ruler, which is a different exercise - an image carries no information about where along the shaft a given point of visual width actually sits, so a photo-based score, whether generated automatically or given by a person looking at the picture, is not locating midshaft or anywhere else in the sense this entry means. It is a different kind of reading, and neither substitutes for the other.