Ovulation Calculator — Find Your Fertile Window

First Day of Last Menstrual Period

Average Cycle Length

days

Average Period Length

days

Show Forecast

cycles ahead

Estimated Ovulation Day

—

🌸 Fertile Window Starts

—

🌸 Fertile Window Ends

—

🩸 Next Period

—

📅 Cycle Day Today

—

📅 Current Cycle Calendar

Period Fertile Ovulation

🌺 Menstrual Cycle Phases

🩸Days 1–5: Menstruation — Uterine lining sheds

🌱Days 6–13: Follicular — Egg matures in ovary

⭐Day 14: Ovulation — Egg released (peak fertility)

🌙Days 15–28: Luteal — Progesterone rises

💡Fertile window: 5 days before + day of ovulation

🔗 Related Health Tools

When Do You Ovulate?

Ovulation typically occurs around 14 days before your next expected period — not necessarily on day 14 of your cycle. If you have a 32-day cycle, you likely ovulate around day 18.

The fertile window spans 5–6 days: the 5 days before ovulation and the day of ovulation itself. Sperm can survive up to 5 days in the reproductive tract, while an egg survives only 12–24 hours after ovulation.

How to Confirm Ovulation

Ovulation predictor kits (OPKs): Detect the LH surge (24–36 hours before ovulation). Most reliable at-home method.

Basal body temperature (BBT): Temperature rises 0.2–0.5°C after ovulation. Requires daily tracking and confirms ovulation after it has already occurred.

Cervical mucus: Becomes clear, stretchy, and egg-white-like at peak fertility — sometimes called "egg white cervical mucus" (EWCM).

Frequently Asked Questions

Can I get pregnant outside my fertile window? ▼

It is very unlikely but not impossible. Sperm can survive up to 5 days, and ovulation timing can vary month to month. Using contraception consistently is the only reliable way to prevent pregnancy.

What are signs of ovulation? ▼

Common signs include: a sharp, brief pain on one side of the lower abdomen (mittelschmerz), increased libido, clear stretchy cervical mucus, a slight rise in basal body temperature, and breast tenderness. Not all women experience noticeable symptoms.

Why is my cycle irregular? ▼

Cycle irregularity can be caused by stress, significant weight change, intense exercise, thyroid disorders, PCOS, perimenopause, or other hormonal conditions. If your cycles are consistently irregular, consult a gynecologist.

How accurate is this ovulation calculator? ▼

This calculator provides estimates based on average cycle patterns. It is most accurate for women with regular cycles. Women with irregular cycles or PCOS may ovulate at unpredictable times. For the most accurate ovulation tracking, use OPK tests or consult a doctor.

⚕️ Medical Disclaimer: This ovulation calculator provides estimates for informational purposes only. It should not be used as a contraceptive method or as a guaranteed fertility planning tool. Individual cycles vary. Consult a healthcare provider or fertility specialist for personalized advice.