Your cycle, by the light of the moon

See your estimated phase and fertile window for any date, alongside that night's moon.

Everything is calculated in your browser. Nothing you enter is saved or sent anywhere. These are estimates, not birth control.

Menstrual Follicular Ovulation Luteal

Four phases, four kinds of support

Hormones shift across your cycle, and so does what helps. Each phase has its own guide and product picks.

Menstrual

Roughly days 1 to 5

Heat, rest, and period care that works for you.

Follicular

After your period

Rising energy and a good time to start something new.

Ovulation

Mid-cycle

Signs to watch for and tools for tracking.

Luteal

Before your period

PMS comfort, steadier routines, and better sleep.

Trying to conceive?

Find your fertile window, start folic acid early, and pick tracking tools that fit how you like to work.

Read the guide
  • How the fertile window works
  • Ovulation tests compared with temperature charting
  • What to ask at a preconception checkup
  • When to talk with a doctor