21 Weeks Pregnant
You’re 21 weeks pregnant — in the second trimester, and 19 weeks to go until your due date. Your baby is about the size of a carrot this week.
How big is your baby at 21 weeks?
Size of a
carrot
Length
~26.7 cm
Weight
~360 g
Last week your baby was about the size of a banana; this week it's grown to roughly a carrot.
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 21
The fetus is now drinking amniotic fluid daily, which helps the digestive system practise and contributes to taste development — flavours from your diet pass into the fluid. Bone marrow is taking over blood-cell production, and rapid eye movements have begun. Movements may now be strong enough for a partner to feel. About the size of a carrot.
Your body at 21 weeks
Common symptoms many people notice around week 21 include:
- Stronger kicks and rolls
- Stretch marks may appear on the belly, breasts, or thighs
- Oily skin or breakouts
- Increased appetite
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 21
- Moisturise skin, though stretch marks are largely down to genetics
- Invite your partner to feel the baby move
- Keep meals balanced as appetite grows
What trimester is 21 weeks?
Week 21 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 21 weeks pregnant?
- 21 weeks pregnant is about 5 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 21 weeks?
- At 21 weeks, the baby is about the size of a carrot, roughly 26.7 cm and around 360 g. These are averages — healthy babies vary, and your provider tracks your baby's own growth curve at scans.
- What trimester is 21 weeks?
- Week 21 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).