➡️ Next Ovulation Date Calculator — Free Fertility Tool
Use our free next ovulation date calculator to find your ovulation day, fertile window, and next period date. Works for all cycle lengths.
Frequently Asked Questions — Ovulation Calculator
How do I calculate my ovulation date?+
Ovulation typically occurs 14 days before your next period. For a 28-day cycle with a March 1 start date, ovulation is around March 15. Enter your LMP and cycle length above for an accurate estimate.
How long is the fertile window?+
The fertile window is approximately 6 days: the 5 days before ovulation plus ovulation day itself. Sperm can survive up to 5 days in the reproductive tract, so having intercourse during this window maximizes conception chances.
Can I rely on this calculator if my periods are irregular?+
This calculator works best with regular cycles. For irregular periods, the fertile window estimate may be less accurate. Track your cycle length over 3+ months to find your average, then use that value.