Safe Period Calculator
Estimate your fertile window and safe days based on your menstrual cycle.
Important Disclaimer: This tool uses the standard rhythm method and provides estimates only.
It is not 100% effective for preventing pregnancy or predicting ovulation, as cycles can vary due to stress, health, and other factors.
Do not rely on this as your sole method of contraception. Consult a healthcare professional for medical advice.
Your Cycle Calendar
Safe Day
Fertile Window
Ovulation Day
Period
How It Works
This calculator assumes ovulation occurs approximately 14 days before the start of the next period. Sperm can survive for up to 5 days, and the egg lives for about 24 hours. Therefore, the "fertile window" includes the days leading up to ovulation and the day of ovulation itself. Days outside this window are generally considered "safe," but the risk of pregnancy is never zero without contraception.