Ovulation & Fertility Calculator
Identify your most fertile days and plan for conception.
Typical cycles are 21-35 days.
Your Fertility Results
Estimated Ovulation Day:
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Most Fertile Window:
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Next Period Start:
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Pregnancy Test Date (Estimated):
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Understanding Your Ovulation Cycle
Ovulation is the phase in a woman's menstrual cycle when a mature ovarian follicle releases an egg. Once released, the egg travels down the fallopian tube, where it can be fertilized by sperm. For couples trying to conceive, timing intercourse during the fertile window is critical.
How the Calculation Works
The standard "Luteal Phase" (the time between ovulation and your next period) is typically 14 days. Our calculator works by subtracting 14 days from your projected next period start date.
- The Fertile Window: This consists of the day of ovulation and the 5 days preceding it. Since sperm can survive inside the female body for up to 5 days, intercourse leading up to ovulation offers the best chance of pregnancy.
- Cycle Variation: If your cycles are irregular, the calculation becomes an estimate. We recommend tracking for at least 3 months to find your average cycle length.
Common Signs of Ovulation
While this calculator provides a mathematical estimate, your body often provides physical cues that ovulation is near:
- Changes in Cervical Mucus: It often becomes clear, stretchy, and slippery (resembling raw egg whites).
- Basal Body Temperature (BBT): A slight dip followed by a sustained increase in resting temperature usually indicates ovulation has occurred.
- LH Surge: Luteinizing Hormone (LH) increases 24-48 hours before ovulation, which can be detected by Ovulation Predictor Kits (OPKs).
- Mild Pelvic Pain: Some women experience a slight twinge or cramp known as mittelschmerz.
Practical Examples
| Scenario | Cycle Length | Approx. Ovulation Day |
|---|---|---|
| Short Cycle | 24 Days | Day 10 |
| Standard Cycle | 28 Days | Day 14 |
| Long Cycle | 35 Days | Day 21 |