Ovulation Calculator
Predict your ovulation date and fertility window based on your cycle length.
Enter the first day of your last menstrual period
Average cycle length: 21-35 days (typical: 28 days)
Your Ovulation Cycle
🎯 Fertile Window
📋 Cycle Phases
Days 1-5: Uterine lining sheds
Days 1-13: Follicle grows, estrogen rises
Day 14: Egg is released (most fertile)
Days 15-28: Progesterone rises, body prepares for period
💡 Ovulation Tips
- • Ovulation typically occurs 12-16 days before next period
- • Sperm can survive 3-5 days, egg survives ~12-24 hours
- • Fertile window is roughly 5 days before to 1 day after ovulation
- • Track basal body temperature (BBT) for more accuracy
- • Look for ovulation signs: cervical mucus changes, cramping
- • This is an estimate; track actual signs for better accuracy
Formula
Estimated Ovulation Date = LMP + (Cycle Length − 14 days)
Fertile Window = 5 days before ovulation to 1 day after ovulation
Next Period Estimate = LMP + Cycle Length
How it works
Estimated Ovulation Date = LMP + (Cycle Length − 14 days) Fertile Window = Ovulation ± 5 days before, 1 day after Next Period (Estimate) = LMP + Cycle Length Standard Cycle: 28 days Range: 21-35 days typical Menstrual Phases: Days 1-5: Menstrual Phase Days 1-13: Follicular Phase Day 14: Ovulation (Peak Fertility) Days 15-28: Luteal Phase Egg Survival: 12-24 hours Sperm Survival: 3-5 days
The ovulation calculator estimates your ovulation date and fertile window based on your menstrual cycle. Enter your last menstrual period (LMP) and cycle length to predict when you're most likely to conceive. Shows your fertile window, next expected period, and detailed cycle phase information.
Why this matters
Understanding your ovulation cycle is essential for family planning, whether you're trying to conceive or avoid pregnancy. Knowing your fertile window helps with natural family planning and increases chances of conception. Tracking cycle patterns helps identify irregularities and potential health concerns.
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Learn more
The complete guide to ovulation calculator
Formulas, examples, and tips explained in plain English