Our simple period calculator can help you identify when you’re likely to menstruate and stay on top of your cycle. Track your menstrual cycle , predict periods and ovulation, and identify fertile days with this easy-to-use period calculator and fertility calendar. The Gynoveda Period Calculator helps you accurately predict your next period , ovulation date, and fertile window— all based on simple details like your last period date and average cycle length. By entering just 3 inputs: This free calculator estimates days in the future during which a person is expected to undergo their period , based on information of previous periods.