Everything we have written about measuring menstrual blood loss — what the numbers mean, and where they come from.
PBAC, the Menstrual Assessment Chart and a clot-size comparison table — the reference for telling a heavy period from a normal one.
Score your own flow on the Pictorial Blood Loss Assessment Chart. Interactive, and nothing you enter leaves your browser.
Cup capacity is the one number on your period that is already measured for you — if you know how to read it.
How a logged pad, tampon or cup becomes a millilitre estimate — the per-product tables, the research behind the 80 ml threshold, and the known limits.
What separates a normal period from a heavy one (the 80 ml threshold), and how PeriodVol turns what you used into millilitres.