How many months is 33 weeks pregnant?

33 weeks is roughly 7½ months. Months are an awkward unit in pregnancy because they do not divide evenly into weeks — a calendar month averages about 4.3 weeks, which is why 40 weeks works out a little over nine months rather than ten. Appointments and scans are always booked in weeks, so weeks are the figure worth carrying.

How big is a baby at 33 weeks?

The NHS publishes around 43.7 cm long, from head to heel for week 33. Rather than one fruit, that length is offered here against eight rulers, each object carrying its own measurement: a five-litre lolly jar (44 cm base to lid), a platypus (45 cm bill to tail), a CD tower, twenty-four discs of it (45 cm top to bottom), a batting pad (45 cm top to bottom), and four more. Published lengths are averages across many babies, not a measurement of any particular one, and a scan estimate that differs is a normal thing rather than a finding.

What trimester is 33 weeks?

Week 33 is in the third trimester, on the commonly published split of weeks 1–12, 13–26 and 27 onward. The boundaries are conventions for talking about pregnancy rather than biological switches — nothing changes overnight at week 13 or week 27.

33 weeks pregnant

What happens at 33 weeks pregnant?

At 33 weeks a baby is around 43.7 cm long, from head to heel, about the size of a five-litre lolly jar. That is roughly 7½ months, in the third trimester, with about 7 weeks to go until 40.

Published length

43.7 cm long, from head to heel

In months

Roughly 7½ months

Trimester

third · 7 weeks to go

What is developing at 33 weeks

The bones are hardening — all except the skull, which stays soft with gaps between the plates so it can move through the birth canal. The immune system is developing as antibodies cross the placenta. The pupils can now widen and narrow in response to light.

The size comparison above is a five-litre lolly jar, which measures 44 cm base to lid. Every comparison on this site is a real object with a real measurement, checked against the published length. The same week is drawn in seven other sets below, from Australian animals to fast food, if this one means nothing to you.

33 weeks, in eight rulers

Every other pregnancy tool measures a baby in fruit. This one offers eight sets to choose from, and each object below carries its real measurement, checked against the 43.7 cm the NHS publishes for week 33. Pick whichever ruler you actually have a feel for. Why not fruit.

Sweet treats
a five-litre lolly jar
44 cm base to lid
Australian animals
a platypus
45 cm bill to tail
The 90s
a CD tower, twenty-four discs of it
45 cm top to bottom
Sport
a batting pad
45 cm top to bottom
Things you already own
a bike pump
44 cm end to end
Gaming
an arcade cabinet's control panel
45 cm side to side
Fast food
an eighteen-inch party pizza
45.7 cm across
Toys
a Lego Technic box
48 cm side to side

Your dates, from 33 weeks

Set to someone who is exactly 33 weeks today, so the due date below is the one that implies. Change the date to your own and everything follows from it — nothing is saved unless you do.

How far along am I?

Your due date

Do not know your due date yet? The due date calculator estimates one from your last period. A dating ultrasound is more accurate than any calendar method — if your pregnancy care team has given you a date, use theirs.

Questions about 33 weeks

How many months is 33 weeks pregnant?: 33 weeks is roughly 7½ months. Months are an awkward unit in pregnancy because they do not divide evenly into weeks — a calendar month averages about 4.3 weeks, which is why 40 weeks works out a little over nine months rather than ten. Appointments and scans are always booked in weeks, so weeks are the figure worth carrying.
How big is a baby at 33 weeks?: The NHS publishes around 43.7 cm long, from head to heel for week 33. Rather than one fruit, that length is offered here against eight rulers, each object carrying its own measurement: a five-litre lolly jar (44 cm base to lid), a platypus (45 cm bill to tail), a CD tower, twenty-four discs of it (45 cm top to bottom), a batting pad (45 cm top to bottom), and four more. Published lengths are averages across many babies, not a measurement of any particular one, and a scan estimate that differs is a normal thing rather than a finding.
What trimester is 33 weeks?: Week 33 is in the third trimester, on the commonly published split of weeks 1–12, 13–26 and 27 onward. The boundaries are conventions for talking about pregnancy rather than biological switches — nothing changes overnight at week 13 or week 27.

Where these numbers come from

NHS — Week-by-week guide to pregnancy — The published length of a baby at each week of pregnancy — measured head to bottom until week 20 and head to heel from week 20 — and what is developing at that stage.
Pregnancy, Birth and Baby — Pregnancy week by week — The Australian Government health service’s week-by-week account of how a pregnancy is counted and what develops at each stage.

General information only, not medical advice. BubSync is not a medical device: these tools do not diagnose, treat or monitor any condition, and using one does not create a clinical relationship. Every baby is different, and these are published ranges rather than targets to hit — they may not apply to your baby, particularly if they were born preterm, are small or large for their age, or have a medical condition. Never delay or disregard advice from a health professional because of something a calculator here showed you. If you are worried about feeding, sleep, weight or wet nappies, contact your child health nurse, midwife or GP — and if your baby seems unwell, floppy, or is difficult to rouse, seek urgent medical care now (000 in Australia).

Written by the BubSync editorial team. Not yet reviewed by an independent clinician. The editorial policy says who writes these pages and how their figures are sourced. Read how we write and check these pages.

Stop doing this maths in your head

Once the counting turns into feeds, sleeps and nappies, BubSync keeps that record shared across everyone caring for your baby.

See how BubSync works All free tools