Ovulation Calculator

Find your fertile window — the days you're most likely to conceive.

How Does the Ovulation Calculator Work?

Ovulation typically occurs about 14 days before your next period starts. For a 28-day cycle, that's around day 14. Your fertile window includes the 5 days before ovulation and the day of ovulation itself — giving you about 6 fertile days each cycle.

Sperm can survive for up to 5 days, while an egg is viable for about 12-24 hours after ovulation. Timing intercourse during your fertile window significantly increases your chances of conception.

Signs of Ovulation

  • Changes in cervical mucus — becomes clear, slippery, and stretchy (like egg whites)
  • Mild pelvic or abdominal pain (mittelschmerz) on one side
  • Slight rise in basal body temperature (0.5-1°F after ovulation)
  • Increased libido
  • Breast tenderness

Tips for Tracking Ovulation

For more accurate tracking, consider ovulation predictor kits (OPKs), tracking basal body temperature daily, or using a fertility monitor. This calculator provides an estimate — individual cycles vary.