How many weeks until my due date?
Pop in your estimated due date below and the countdown does the rest — weeks and days left, how far along you are, your trimester, and a progress bar for the whole 40-week journey.
How many weeks until your due date?
Worked out in your browser from your local date. An EDD is an estimate — your provider’s dating always takes precedence.
How the countdown works
A pregnancy is counted as 40 weeks — 280 days — measured from the first day of your last menstrual period, not from conception. Your estimated due date (EDD) is simply that start point plus 280 days. So “how many weeks until my due date” is just the gap between today and that date, while “how many weeks pregnant” is the same sum from the other end.
Knowing where you are helps with the practical things — booking antenatal appointments, planning leave, a baby shower, and getting the hospital bag ready before the final stretch. The most accurate dating comes from an early ultrasound in the first trimester, which is why a scan can sometimes nudge your due date a few days either way.
The three trimesters
The 40 weeks are traditionally split into three stages, each with its own character:
Your due date is an estimate — really
It’s easy to treat the EDD as a fixed appointment, but only about 1 in 20 babies (roughly 4–5%) actually arrive on the exact day. The rest spread out across the weeks around it, and going a little past — especially with a first baby — is entirely normal.
That’s why obstetricians no longer lump everything into one “term” bracket. Since 2013, ACOG and the Society for Maternal-Fetal Medicine have used a more precise ladder, because outcomes differ even within those final weeks:
| Early term | 37 0/7 – 38 6/7 weeks |
| Full term | 39 0/7 – 40 6/7 weeks |
| Late term | 41 0/7 – 41 6/7 weeks |
| Postterm | 42 0/7 weeks and beyond |
In other words, “full term” is the window from 39 weeks 0 days through 40 weeks 6 days — a week either side of the due date — where outcomes are generally best. Anything from 37 weeks onward is no longer called premature.
Common questions
This page and calculator give general information, not medical advice. Every pregnancy is different — for anything about your dates, your health or your baby’s, your midwife or doctor is the right person to ask.
Sources
- American College of Obstetricians and Gynecologists (ACOG) & SMFM — Committee Opinion 579, “Definition of Term Pregnancy” (early/full/late/postterm).
- ACOG — “Method for Estimating Due Date” (40 weeks / 280 days from LMP; early-ultrasound dating).
- NICHD & Mayo Clinic — pregnancy week-by-week and term redefinition.
Related
Forty weeks, counted one at a time — though the only date that really matters is the one your baby chooses.