Step 1: Enter Your Last Period Date

Enter the first day of your last menstrual period using the date picker. This is the starting point for all calculations.

Step 2: Set Your Cycle Information

Enter your average cycle length (typically 21-35 days) and period duration (typically 3-7 days). You can adjust these based on your personal cycle.

Step 3: View Your Predictions

Click Calculate to see your next period dates, ovulation day, fertile window, and days until your next period. The phase indicator shows your current cycle phase.

Key Features

• Accurate period and ovulation predictions
• Fertile window identification for family planning
• Cycle phase tracking (period, ovulation, safe period)
• Simple and intuitive interface
• 100% private — all data stays in your browser
• Completely free to use

Common Uses

• Cycle Tracking:
  Track and predict your menstrual cycle with personalized predictions
• Family Planning:
  Identify fertile windows and ovulation days for pregnancy planning
• Health Monitoring:
  Monitor cycle regularity and detect potential irregularities early
• Lifestyle Planning:
  Plan vacations, events, and activities around your cycle

Frequently Asked Questions