How many months is 28 weeks pregnant?
Twenty-eight weeks is seven months — and a milestone, because it’s the first week of the third trimester, the final stretch. (Yes, 28 weeks really is “7 months,” even though the week-to-month maths is famously fiddly.)
Convert any pregnancy week
Slide to any week and see the month and trimester it falls in.
28 weeks = your seventh month, and the very start of the third trimester.
Based on the standard pregnancy-month chart. A calendar month isn’t exactly four weeks, so sources vary by a few days.
Why weeks and months don’t line up
The confusion is real, and it’s not your maths. A calendar month averages about 4.3 weeks, not a tidy four, so the two systems drift apart as the weeks add up. By the common pregnancy-month chart, week 28 lands at the start of month seven. Divide 28 by 4.3 instead and you get about 6.5 — which is why some sources say “six and a half months.” Both are describing the same point; they’re just counting differently.
The cleaner way to think about it: pregnancy is around 40 weeks, or about nine months — not ten — split into three trimesters of roughly three months each. Reaching 28 weeks means you’ve finished the second trimester and started the third.
What’s happening at 28 weeks
At 28 weeks the baby is roughly the size of a large eggplant — about 1 kg (2.2–2.5 lb) and 36–38 cm head to heel — and entering a phase of rapid growth and brain development. A few of the changes around this point:
Common questions
This page covers the week-to-month maths and general development — it isn’t medical advice. Every pregnancy is different, so anything about your own milestones, symptoms or baby’s growth is best checked with your midwife or doctor.
Sources
- Mayo Clinic — fetal development, third trimester (size, weight, eyelids, brain).
- American Pregnancy Association & major maternity guides — 28-week measurements and the third-trimester milestone.
- Standard pregnancy-month charts — week-to-month and trimester mapping.
Related
Seven months in, two trimesters down, one to go — the home straight begins at week 28.