Free tool
Map your cycle, unlock your fertile days
See your ovulation date, 6-day fertile window and which of the four cycle phases you’re in right now — with a visual cycle ring and shareable summary. No sign-up required.
Ovulation Calculator
Standard cycle method
Enter your last period date and cycle length to reveal your fertile window, current cycle phase and a personalised calendar.
Menstrual
Follicular
Ovulation
Luteal
Map your cycle and your fertile days
Enter your last period and cycle length to see your fertile window, ovulation day, current cycle phase — and a shareable summary card.
Pro tip: Sperm can survive up to 5 days in the reproductive tract, which is why the fertile window starts before ovulation. For higher accuracy, track basal body temperature and cervical mucus alongside this calculator.