16 Weeks Pregnant
You’re 16 weeks pregnant — in the second trimester, and 24 weeks to go until your due date. Your baby is about the size of a avocado this week.
How big is your baby at 16 weeks?
Size of a
avocado
Length
~11.6 cm
Weight
~100 g
Last week your baby was about the size of a apple; this week it's grown to roughly a avocado.
Sizes are averages from standard fetal-growth references. Every baby grows at its own pace — your provider tracks yours at scans.
Baby development at week 16
The fetus can now make small, coordinated movements, and the muscles of the back are strong enough to straighten the head and neck. The eyes are slowly moving toward the front of the face and beginning to make small side-to-side movements. The heart is pumping around 25 litres of blood a day. About the size of an avocado.
Your body at 16 weeks
Common symptoms many people notice around week 16 include:
- Some begin to feel the first flutters of movement ('quickening')
- A rounder, more visible bump
- Mild backache
- Forgetfulness ('pregnancy brain') for some
Symptoms vary enormously from person to person and pregnancy to pregnancy. Not having a symptom on this list is just as normal as having it.
Tips for week 16
- First movements may feel like bubbles or flutters — easy to miss early on
- Support your back with good posture and supportive shoes
- The anatomy scan is usually scheduled for the next few weeks
What trimester is 16 weeks?
Week 16 falls in the second trimester. As a quick map: the first trimester runs weeks 1–13, the second covers weeks 14–27, and the third is week 28 through birth (a due date is set at 40 weeks). Want your own dates? Our Pregnancy Due Date Calculator shows your due date and exactly how far along you are today.
The second trimester (weeks 14–27) is the stretch many people find most comfortable: early nausea usually fades, energy returns, and the bump becomes visible. The big checkpoint is the mid-pregnancy anatomy scan around week 20, and you'll likely feel the first movements during these weeks.
Frequently asked questions
- How many months is 16 weeks pregnant?
- 16 weeks pregnant is about 4 months. Pregnancy months don't divide evenly into 4-week blocks, so week-to-month conversions are approximate — most providers track pregnancy by week, not month.
- How big is the baby at 16 weeks?
- At 16 weeks, the baby is about the size of a avocado, roughly 11.6 cm and around 100 g. These are averages — healthy babies vary, and your provider tracks your baby's own growth curve at scans.
- What trimester is 16 weeks?
- Week 16 is in the second trimester. The first trimester is weeks 1–13, the second is weeks 14–27, and the third is weeks 28 to birth (around week 40).