How it works
Doctors estimate the due date by adding 280 days (40 weeks) to the first day of the last menstrual period, adjusted if your cycle is longer or shorter than 28 days. An early ultrasound gives the most accurate date.
Register your pregnancy early with your doctor or the nearest government health centre for antenatal check-ups, iron and folic acid, tetanus vaccination and scans.
Frequently asked questions
How accurate is a due date?
It is an estimate. Only a small share of babies arrive exactly on the due date; most are born within two weeks either side.
Note: This tool gives general estimates for healthy adults. It is not medical advice or a diagnosis. Talk to a doctor about your own results.