Complete guide: Pregnancy Due Date
Updated:
LMP due date adds 280 days to the first day, with an illustrative cycle −28 adjustment for regular cycles. A genuinely known conception adds 266 days. An established clinical date is used directly without replacing it.
Weeks represent gestational age, counted roughly two weeks before conception, not fetal age. First trimester ends before 14 weeks, second before 28. Initial dates are examples and the reference date is explicit so a shared link reproduces the same estimate.
Early ultrasound and obstetric assessment may establish a more accurate date; irregular cycles, assisted reproduction and uncertain LMP require clinical judgement. Does not confirm pregnancy, viability or fetal growth. Past the estimated date consult your obstetric team; a calculation does not determine when to start or delay care.
How it works
- 1Choose LMP, known conception or clinical due date.
- 2Enter the method date and reference date.
- 3Check date and gestational age with your obstetric team.
Frequently asked questions
Does intercourse date equal conception?
No. Ovulation and fertilization can differ; use LMP or an obstetric date if conception is unknown.
Are values preserved when sharing?
The link retains entered values. Weight, dates and other health data are included in the link: share only with people you want to see them.