Ovulation Calculator
Track your menstrual cycle, predict ovulation dates, and identify your most fertile days with our free online ovulation calculator.
Category: Fitness & Health
The average menstrual cycle is 28 days, but it can range from 21 to 35 days.
Ovulation Calculator
Fill in your details and click Calculate to predict your ovulation and fertile window.
Frequently Asked Questions
When does ovulation occur in the menstrual cycle?
Ovulation typically occurs about 14 days before the start of your next period. In a 28-day cycle, this would be around day 14, but can vary based on your cycle length. The fertile window includes the day of ovulation and the five days before it.
How can I tell if I'm ovulating?
Signs of ovulation may include changes in cervical mucus (becoming clearer and more slippery), a slight increase in basal body temperature, mild pelvic pain or cramping (mittelschmerz), increased sex drive, and breast tenderness. Ovulation predictor kits can also detect hormone changes that indicate ovulation.
How accurate is an ovulation calculator?
An ovulation calculator provides estimates based on the average timing of ovulation in your cycle. It's most accurate if you have regular cycles. For irregular cycles, the predictions may be less reliable. Combining calendar tracking with physical ovulation signs or ovulation predictor kits can improve accuracy.
How long is the fertile window?
The fertile window is typically about 6 days - the 5 days before ovulation plus the day of ovulation itself. This is because sperm can survive in the female reproductive tract for up to 5 days, while an egg remains viable for about 24 hours after ovulation.