Ovulation Calculator

About the Ovulation Calculator

Timing intercourse around ovulation dramatically increases conception chances — the fertile window spans approximately 5 days before ovulation and the day of ovulation itself, with peak fertility in the 2 days before. Our ovulation calculator predicts your most fertile days based on your cycle length, helping you plan for conception or use natural family planning methods.

How It Works

Ovulation typically occurs 14 days before the next expected period, regardless of cycle length. For a 28-day cycle: ovulation ≈ day 14. For a 32-day cycle: ovulation ≈ day 18. For a 26-day cycle: ovulation ≈ day 12. The fertile window spans 5 days before ovulation through ovulation day. Our calculator projects fertile windows for the next 6 cycles based on your average cycle length.

Tips & Best Practices

• ✓Cycle length varies naturally by 2-7 days — track multiple cycles before relying solely on calculations.
• ✓Basal body temperature (BBT) rises 0.2°C after ovulation, confirming it occurred.
• ✓LH surge (positive OPK test) occurs 24-48 hours before ovulation — the best timing window.
• ✓Cervical mucus becomes clear and stretchy (like egg whites) in the days before ovulation.
• ✓Sperm survive 3-5 days in the female reproductive tract, making pre-ovulation intercourse effective.

Who Uses This Calculator

Couples trying to conceive, women using the fertility awareness method for contraception, and those undergoing fertility treatments timing intercourse with IUI or timed intercourse cycles all rely on ovulation tracking.