How to calculate ovulation?

For a 28-day cycle, ovulation typically occurs 14 days before the next period. This tool calculates your ovulation day and fertile window based on your cycle length and last period date.

What is the fertile window?

The fertile window is the period when conception is most likely, typically 5 days before ovulation plus ovulation day itself, totaling about 6 days. Sperm can survive 3-5 days, and the egg survives 12-24 hours.

How accurate is this calculator?

This tool uses standard ovulation calculation methods and is fairly accurate for women with regular cycles. However, actual ovulation may vary due to stress, illness, or medication.

What if my cycle is irregular?

For irregular cycles, use the average length of your last 3-6 cycles. For severely irregular cycles, consult a gynecologist.

When is the best time to conceive?

The highest conception rates occur 1-2 days before ovulation (~25-28%), compared to ovulation day (~8-10%).

What are physical signs of ovulation?

Common signs include: clear, stretchy cervical mucus (egg-white consistency), slight rise in basal body temperature (0.3-0.5°C), mild lower abdominal pain (mittelschmerz), breast tenderness, and increased libido.

Fertility & Ovulation Calculator

Health

Free online fertility & ovulation calculator. Predict ovulation day and fertile window based on menstrual cycle. Calendar view with conception window. 100% client-side, no data upload.

📅 Enter Information

Last Period Date

Cycle Length (days)

Period Duration (days)

Luteal Phase (days)(default 14)

🗓️ Cycle Calendar

Period Fertile Ovulation

📅 Enter Information

📊 Results

🗓️ Cycle Calendar

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