Method
What to write down
A reading without its conditions is not data; the log needs date, state, method, site, instrument and all three raw readings, not just the answer.
A single number written on its own is close to useless six months later. The point of a log is not to watch a figure change - it barely does - but to give you enough context to work out, later, why two sessions disagreed. That means recording the conditions, not just the result.
Why the log is for variance, not progress
Nobody's length changes month to month in a way worth tracking with a spreadsheet. What does move, session to session, is your technique: how hard you pressed, whether you took three readings or one, whether the room was cold. A log that only stores the final centimetre figure throws away the one thing that would let you tell a real difference from noise the next time two sessions disagree. Treat it as a lab notebook for a measurement you are trying to get right, not a diary of a number you expect to change.
The fields, and the error each one catches
Six fields cover almost everything that moves a reading.
| Field | What it catches |
|---|---|
| Date and time | Time-of-day effects, and whether two sessions are close enough together to compare directly |
| State | Flaccid, stretched flaccid, or erect - the single biggest source of disagreement between two of your own numbers |
| Method | Bone-pressed or not, dorsal or another line - see the method line convention for how to write this compactly |
| Site | Base, midshaft or glans for girth; without it a girth number is not repeatable even by you |
| Instrument | Rigid ruler, cloth tape, or paper strip - which one you used, and what that costs you |
| Raw readings | All three (or five) numbers you actually read, not just the value you reported |
Skip any of these and a discrepancy six months from now has no way to be explained - it is just two numbers that disagree, and you have lost the information that would tell you which one, if either, to trust. None of the six fields is optional in practice: leaving out even one turns the row from a record you can reason about back into a bare figure, which is the exact problem the log exists to solve.
Raw readings, not just the median
The field people drop first is the raw readings, and it is the one that matters most. A median or mean is a single derived number; the three or five readings behind it are the actual data, and they are what let you compute an honest uncertainty later, or notice that your spread has widened, which is itself information about your technique that session. Once you have thrown the raw readings away and kept only the summary, you cannot get that back. Where the error in a self-measurement actually comes from is mostly visible in the spread of the raw numbers, not in any single one of them.
A worked row
A filled-in row looks like this:
2026-03-14, 19:40, erect, bone-pressed / dorsal, midshaft (girth), rigid ruler + cloth tape, length 15.1/15.0/15.2 cm, girth 12.4/12.3/12.5 cm
Nothing in that line is a judgement. It is a record of what was done and what was read, which is exactly what makes it usable later, by you or by anyone comparing it to a published figure. For a version of this you can keep somewhere quicker to reach than a spreadsheet, a one-page measurement card condenses the same six fields onto something you can print and fill in by hand.
What a log is not for
A log like this produces a number with a method attached to it, which is a different thing from a score. If what you actually want is a subjective read on a photograph, that is a different category of output entirely, and the honest place to say so is a site built for it, like Rate Cock - a log has no equivalent to hand you, and shouldn't pretend to. A photo-rating score, the kind Penis Rater produces, has no raw-readings row behind it either, because it is a position among images rather than a distance built up from repeats. An image-based tool also has no access to your raw readings at all, since it never takes a physical measurement in the first place - which is one more reason the two records answer different questions. A written log likewise isn't a person's opinion recorded over time, the way a reviewer's notes might be; it has no opinion in it, only fields. Keep the two apart, and the log stays useful for exactly what it is: a way to tell your own noise from a real difference the next time two of your sessions don't agree.