24 weeks pregnant

What happens at 24 weeks pregnant?
At 24 weeks a baby is around 30 cm long, from head to heel, about the size of a hollow chocolate Santa. That is roughly 5½ months, in the second trimester, with about 16 weeks to go until 40.
Published length
30 cm long, from head to heel
In months
Roughly 5½ months
Trimester
second · 16 weeks to go
What is developing at 24 weeks
The lungs begin making surfactant, the substance that stops the air sacs collapsing between breaths. Twenty-four weeks is the point from which many health services describe a pregnancy as viable. The face is fully formed, eyelashes and eyebrows included.
The size comparison above is a hollow chocolate Santa, which measures 30 cm hat to boots. 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.
24 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 30 cm the NHS publishes for week 24. Pick whichever ruler you actually have a feel for. Why not fruit.

Sweet treats
a hollow chocolate Santa
30 cm hat to boots

Australian animals
a sugar glider, tail included
32 cm nose to tail tip

The 90s
Buzz Lightyear
30.5 cm head to boots

Sport
a boxing glove
30 cm cuff to knuckles

Things you already own
a 30 cm ruler
30 cm end to end

Gaming
an Xbox Series X
30.1 cm top to bottom

Fast food
a twelve-inch pizza
30.5 cm across

Toys
Buzz Lightyear
30.5 cm head to boots
Your dates, from 24 weeks
Set to someone who is exactly 24 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?
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 24 weeks
- How many months is 24 weeks pregnant?
- 24 weeks is roughly 5½ 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 24 weeks?
- The NHS publishes around 30 cm long, from head to heel for week 24. Rather than one fruit, that length is offered here against eight rulers, each object carrying its own measurement: a hollow chocolate Santa (30 cm hat to boots), a sugar glider, tail included (32 cm nose to tail tip), Buzz Lightyear (30.5 cm head to boots), a boxing glove (30 cm cuff to knuckles), 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 24 weeks?
- Week 24 is in the second 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.
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.
