Moon and the menstrual cycle

2 November 2026 at 12:00 GMT: last quarter, 42.9% illuminated, 22.84 days since new Moon.

UK default: Europe/London (GMT/BST).
Phase
Last Quarter
Illumination
42.91%
Lunar age
22.840 days
Phase angle
278.29°
Earth–Moon distance
374,780 km
Brown lunation
1284

Two different cycles

A lunar phase cycle averages 29.53 days. Menstrual cycle length varies between people and from one cycle to another. In a 2021 study of 529 women aged 25–39, menstrual onset had no overall association with lunar phase.

Enter a recorded cycle-start date above to label it with its actual Moon phase. Tracking records a past event; a Moon phase does not determine ovulation, a fertile window or contraception timing.

Komada et al., 2021.