Safe Period Calculator
Estimate ovulation, fertile days, and safe window with a cycle calendar.
Safe Period Calculator
Estimate ovulation, fertile window, and safe days by calendar method
Results update instantly with your inputs
Cycle Overview
Please select last period start date
Calendar Forecast
Period
Fertile
Ovulation
Safe
Important Note
Calendar-based safe period estimation is not a reliable contraceptive method. Stress, illness, and lifestyle changes can shift ovulation.
About This Tool
This safe period calculator uses the calendar method to estimate ovulation based on average cycle length and luteal phase length, producing fertile and safe windows. It includes a cycle calendar, key dates, and day counts for easy tracking. Cycle variability can shift ovulation, so results are for reference only.
Features
- 📅 Cycle Calendar: Visual daily view of safe and fertile days for multiple months
- 🎯 Key Dates: Ovulation, fertile window, and next period estimates
- 🧮 Day Stats: Safe days, fertile days, and period days at a glance
- ⚙️ Advanced Settings: Adjustable luteal phase and display duration
- 📱 Responsive Layout: Clean on mobile and desktop
- 🛡️ Privacy First: All calculations run locally