Period Calculator
Track your menstrual cycle, predict your next period, and understand your fertile window. Get personalized insights for better reproductive health planning.
Average cycle length is 28 days
Average period length is 5 days
Enter your cycle details to see predictions
Frequently Asked Questions
How is the menstrual cycle calculated?
The menstrual cycle is calculated from the first day of one period to the first day of the next period. While 28 days is considered average, normal cycles can range from 21 to 35 days.
What is ovulation and when does it occur?
Ovulation is when an egg is released from the ovary. It typically occurs about 14 days before your next period starts. This is usually around day 14 of a 28-day cycle, but can vary based on your cycle length.
What is the fertile window?
The fertile window is the time when pregnancy is possible. It includes the 5 days before ovulation and the day of ovulation itself. This is because sperm can live up to 5 days in the body, while an egg lives for about 24 hours.
How accurate are period predictions?
Period predictions are most accurate for people with regular cycles. Factors like stress, diet, exercise, and medical conditions can affect cycle regularity. It's best to track your cycle over several months for more accurate predictions.
What can affect cycle length?
Many factors can affect cycle length, including stress, significant weight changes, excessive exercise, hormonal conditions, medications, and age. If you notice significant changes in your cycle, consult a healthcare provider.
When should I consult a doctor about my cycle?
Consult a doctor if you experience: cycles shorter than 21 or longer than 35 days, irregular periods, severe pain, heavy bleeding, bleeding between periods, or if you're trying to conceive and haven't succeeded after a year.