Due Date Calculator
Work out your estimated due date from the first day of your last period. You get the approximate date, how many weeks along you are, and your current trimester.
Due date calculator
Enter the first day of your last period to estimate your due date and see how far along you are.
Choose a date to see your results.
How is a due date calculated?
The estimated due date is the first day of your last menstrual period plus 280 days (40 weeks). If your cycle runs longer or shorter than 28 days, the result shifts by the difference. It is an estimate, not an appointment: fewer than 5% of babies arrive on the exact date, and birth anywhere between weeks 37 and 42 is considered full term.
This guide is for general information and reassurance — it isn't medical advice. Always follow your doctor or midwife for your own pregnancy.