Period Calculator

A normal menstrual cycle ranges from 21 to 35 days. The average is 28 days, but your cycle is considered regular as long as it comes at consistent intervals within this range.

Cycle length is counted from the first day of one period to the first day of the next period.

The fertile window is typically 6 days: the 5 days before ovulation and the day of ovulation. This is when pregnancy is most likely to occur.

Ovulation usually occurs about 14 days before the start of your next period in a regular 28-day cycle.

The menstrual cycle has four main phases:

• Menstrual Phase (Days 1-5): Period bleeding occurs
• Follicular Phase (Days 1-13): Uterine lining rebuilds
• Ovulation Phase (Day 14): Egg is released
• Luteal Phase (Days 15-28): Body prepares for possible pregnancy

Period predictions are estimates based on your average cycle length. Actual cycles can vary by a few days due to factors like stress, diet, exercise, illness, or travel.

For more accurate predictions, track your cycle for at least 3 months to establish your personal pattern.

Irregular periods can be caused by:

• Stress or lifestyle changes
• Significant weight loss or gain
• Hormonal imbalances (PCOS, thyroid issues)
• Birth control or medications
• Perimenopause or menopause

Consult a healthcare provider if irregularities persist.