Pregnancy Due Date Calculator
Pregnancy due date calculator: estimated due date, conception date and current week from the first day of your last period (Naegele's rule).
EDD = LMP + 280 d
How to use this calculator
- Type your input in the box.
- The result updates as you type.
- Use “Copy result” or “Copy link” to share it.
The due date is 280 days (40 weeks) after the first day of the last menstrual period, adjusted for cycles longer or shorter than 28 days.
Only about 4 % of babies arrive on their due date; most are born within two weeks of it.
For general information only; it does not replace advice from a doctor or other health professional.
Frequently asked questions
Last period started 1 January 2026: due date?
8 October 2026.