Ovulation Calculator
Predict fertile window & ovulation
How to Use
Enter last period date
Input the first day of your last menstrual period.
Set cycle length
Enter your average cycle length (typical is 26-32 days).
Choose cycles to show
Select how many upcoming cycles to display.
View fertile window
See your ovulation date, fertile window (6 days), and most fertile days for each cycle.
Frequently Asked Questions
When is the best time to conceive?
The most fertile days are the 2-3 days before ovulation and the day of ovulation. Sperm can survive 5 days, but the egg only 12-24 hours.
How accurate is ovulation prediction?
This calculator estimates based on average cycles. Actual ovulation can vary by several days. OPK tests or basal body temperature tracking are more accurate.
What factors affect ovulation?
Stress, illness, travel, weight changes, and hormonal conditions can all shift ovulation timing.
Can I use this for contraception?
No, this is not reliable for contraception. Ovulation can be unpredictable, and this calculator provides estimates only.
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