Due Date Calculator
Find your due date and how many weeks pregnant you are today.
The day you think the egg was fertilised, usually about 2 weeks after your period started.
Key dates
Only about 1 baby in 25 arrives on the exact due date. Most arrive within two weeks either side. This is an estimate, not medical advice. Your midwife or doctor may change the date after a scan.
Questions
How is the due date calculated?
A pregnancy is counted as 40 weeks (280 days) from the first day of your last period. If your cycle is longer or shorter than 28 days, the date moves by the difference. From conception it is 266 days. After IVF it is 261 days from a day 5 transfer and 263 days from a day 3 transfer. From a scan, the weeks and days it measured are counted back to day zero.
Why does it say 5 weeks when I conceived 3 weeks ago?
Doctors start counting from the first day of your last period, about two weeks before conception. That is why a pregnancy lasts 40 weeks, not 38.
Is my information private?
Yes. Everything is worked out on your device and only saved on your device, so you see your result again next time. Your data is never sent anywhere. Start over clears it.