Home Ovulation Calculator Daily Quotes July 28, 2025 Premium Ovulation Calculator Ovulation Calculator Track your fertility window with precision First day of your last period Average cycle length (days) ? Typically 28 days, but can vary between 21-35 days Luteal phase length (days) ? Time between ovulation and next period (usually 12-16 days) Calculate Fertility Window ✓ Next ovulation date -- ✓ Fertility window -- ✓ Next period expected -- Facebook Twitter