Fertility Window Calculator

Calculate your 6-day fertility window including peak ovulation days for the best chances of conception.

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12,500+ users
Updated January 2025
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Fertility Window Calculator

Track your most fertile days

Understanding Your Fertile Window

Your fertile window is approximately 6 days: 5 days before ovulation plus ovulation day. The 2-3 days before ovulation are your most fertile.

Your Cycle Information

The day your last period started

Typical range: 21-35 days (average is 28)

Understanding Your Cycle Phases

Tips for Conception

Timing is Key

Have intercourse during your fertile window, especially 2 days before ovulation

Track Symptoms

Monitor cervical mucus, basal body temperature, and ovulation signs

Healthy Lifestyle

Maintain healthy weight, exercise moderately, and manage stress

Prenatal Vitamins

Start taking folic acid (400-800 mcg) daily before conception

Signs of Ovulation

Cervical Mucus

Clear, stretchy, egg-white consistency

Basal Body Temperature

Slight rise (0.5-1°F) after ovulation

Ovulation Pain

Mild cramping on one side (mittelschmerz)

Increased Sex Drive

Natural libido boost around ovulation

Fertility Facts

Sperm Lifespan:

Sperm can survive in the female reproductive tract for 3-5 days, which is why the fertile window extends before ovulation.

Egg Lifespan:

An egg survives for 12-24 hours after ovulation, making timing crucial for conception.

Irregular Cycles:

If your cycles vary by more than 7 days, consider tracking with ovulation predictor kits or consulting a healthcare provider.

Conception Rates:

Healthy couples have about a 20-25% chance of conceiving each cycle. Most couples conceive within 6-12 months of trying.

Medical Disclaimer

This calculator provides estimates based on typical cycle patterns. For personalized fertility advice, irregular cycles, or conception concerns, please consult your healthcare provider or fertility specialist.