Due Date Calculator
Find out when your little one will arrive
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How is my due date calculated?
Your due date is estimated by adding 280 days (40 weeks) to the first day of your last menstrual period (LMP), known as Naegele's rule. Only about 5% of babies arrive on their exact due date — most are born within two weeks before or after.
Calculation methods
Last Period (LMP): The most common method. Add 280 days from the first day of your last period.
Conception Date: If you know when you conceived, we subtract 14 days to estimate LMP, then add 280 days.
Ultrasound: Based on your baby's measurements during an early ultrasound scan (most accurate between weeks 8-12).