Due date calculator
Estimate your due date, how many weeks pregnant you are and your trimester from the first day of your last period or your conception date.
This is an estimate, not medical advice. Few babies arrive exactly on their due date, and your doctor or midwife may change it after an ultrasound.
How is the due date calculated?
Pregnancy is counted from the first day of your last menstrual period. The estimated due date is that day plus 280 days (40 weeks), a method known as Naegele's rule.
If your cycle is longer or shorter than 28 days, the date moves by the difference. If you know your conception date, the due date is about 266 days after conception.
A first-trimester ultrasound can date a pregnancy more precisely. Always go over the dates of your own pregnancy with your doctor or midwife.
Pregnancy week by week
Free pregnancy tools
Follow your pregnancy week by week with Koza
Your own pregnancy week, due date calculator, kick counter, contraction timer and weight tracking in one app. Free on iPhone and Android.
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