Ovulation Calculator
Estimate your ovulation day and fertile window for the next three cycles, plus a due date if you conceive.
Ovulation date
24 Jul 2026
Fertile window
19 Jul 2026 – 25 Jul 2026
Next period
07 Aug 2026
Test on
08 Aug 2026
Due date if conceived
16 April 2027
Next 3 cycles
- Cycle 1Fertile 19 Jul 2026 – 25 Jul 2026
- Cycle 2Fertile 16 Aug 2026 – 22 Aug 2026
- Cycle 3Fertile 13 Sep 2026 – 19 Sep 2026
Health disclaimer: This result is for general informational purposes only and is not medical advice. Individual health needs vary — consult a qualified healthcare professional before making health, diet, or medical decisions.
📐 About This Calculator
Ovulation typically occurs about 14 days before your next period (the luteal phase). The fertile window spans the five days before ovulation plus the ovulation day.
Variable Definitions:
- • Cycle length = Days from one period start to the next
- • Luteal phase = Days from ovulation to next period (≈14)
✅ Best used for:
- • Family planning
- • Understanding your cycle
- • Timing a pregnancy test
⚠️ Limitations:
- • An estimate — cycles vary month to month
- • Not a contraceptive method
📖 How Ovulation is Calculated
The fertile window
Sperm can survive several days, so the days leading up to ovulation are the most fertile. This calculator marks the five days before ovulation plus the ovulation day.
Cycle-length adjustment
Shorter or longer cycles shift ovulation earlier or later. Enter your typical cycle length for a better estimate.