Pregnancy calculator
This is an estimate. Your doctor confirms the due date with an ultrasound scan.
FAQ
How is the due date calculated?
We add 280 days (40 weeks) to the first day of your last period, adjusted if your cycle is longer or shorter than 28 days.
Do most babies arrive on the due date?
No. Only a small share arrive on the exact day; most come within two weeks either side.
When does each trimester start?
The first trimester runs to the end of week 13, the second from week 14 to 27, and the third from week 28 to birth.