How Big Is That Baby in There? Your Week-By-Week Pregnancy Guide to Your Baby's Size

Wondering about the size of Baby week by week? Whether you're at week 6 or 36, check out our pregnancy guide!

You're preggers, and whether you can still button your favorite jeans or you're as big as a house, you're probably wondering just how much of that heft you're hauling around is actually baby. (The answer, of course, depends. At week 6? Not so much. At week 36? Yeah, you're carrying around a melon.) But really, how big is that little guy? The size of a lentil? A lime? A pineapple? To keep track, check out our week-by-week guide to your baby's size.

4 Weeks: A Sesame Seed

size of baby week 4

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At this point, you might not even know you're expecting. Meanwhile, the embryo is less than 1/10th of an inch in length, about the size of a sesame seed.

 

5 Weeks: A Lentil

size of baby week 5

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Your baby's heart is beating steadily, but he looks like a tadpole and is still tiny -- the size of a lentil (just over 1/10th of an inch.) Keep in mind that early in pregnancy, a baby's length is measured from the crown of his head to the bottom of his, well, bottom!

 

6 Weeks: A Peanut

size of baby week 6

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By this point, your doctor should be able to detect a heartbeat through a vaginal ultrasound. Your future child is now around ¾ of an inch, about the size of a peanut.

 

7 Weeks: A Raspberry

size of baby week 7

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Your baby has reached a milestone: He's about an inch long this week, though he still weighs a fraction of an ounce. He's as big as a raspberry.

 

8 Weeks: A Grape

size of baby week 8

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By this week, your baby is comparable to a grape, slightly over 1 inch long.

 

9 Weeks: A Strawberry

size of baby week 9

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Your little one is 1.67 inches this week and still weighs barely anything -- he’s roughly the size of a strawberry.

 

10 Weeks: A Baby Carrot

size of baby week 10

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At a little over 2 inches, your baby is the length of a baby carrot. He also weighs about ¼ of an ounce, and his fingernails, toenails and hair will start to develop this week.

 

11 Weeks: A Lime

size of baby week 11

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Your baby is about 2 ½ inches long, the length of a small lime. He weighs half an ounce, and his tiny head is almost as big as the rest of his body.

 

12 Weeks: A Clementine

size of baby week 12

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What a big girl! Your baby finally weighs 1 ounce and, at a little over 3 inches long, is the size of a clementine. She’s now developing reflexes like sucking.

 

13 Weeks: An Apricot

size of baby week 13

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Your baby is now the size of an apricot (3 ¾ inches long and 1¼ ounces.) His tiny fingers now have fingerprints, and his body is covered in a fine hair called lanugo.

 

14 Weeks: A Large Lemon

size of baby week 14

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At just over 4 inches and a little less than 2 ounces, your baby is the size of a large lemon. She also might start sucking her thumb now.

 

15 Weeks: An Apple

size of baby week 15

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The apple of your eye is the size of the same fruit, about 4 ¾ inches long and weighing in at 2 ounces.

 

16 Weeks: An Avocado

size of baby week 16

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Your baby is as big as an avocado -- about 5.31 inches long and around 2 ½ ounces. If you've been experiencing morning sickness, it may start to subside around now.

 

17 Weeks: A Sweet Potato

size of baby week 17

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At 4 ounces and 6 ½ inches long, your baby has grown to the size of a sweet potato. You might want to start sweet-talking to him: His ears are fully formed and his sense of hearing is becoming fine-tuned!

 

18 Weeks: A Green Pepper

size of baby week 18

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Your baby is about 5 ½ ounces and a little over 6 inches long, the size of a green pepper. If you're eager to find out the sex of your baby, you might be able to tell at this point!

 

19 Weeks: An Onion

size of baby week 19

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As big as a large onion (slightly under 7 inches long and about 7 ounces), your baby is starting to grow hair on his tiny head. If you're having a girl, you might be amazed to find out her ovaries have already produced millions of eggs.

 

20 Weeks: A Mango

size of baby week 20

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Your baby is 7 ¾ inches long and is around the same weight as a mango (about 9 ounces). He's producing meconium, the dark, tar-like substance that makes up his first bowel movements. You may even have felt that mom-to-be milestone -- your baby kicking! -- at this point.

 

21 Weeks: A Grapefruit

size of baby week 21

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Up until now, your baby's length was measured from the crown of his head to his bottom. From now on, his length is measured from the top of his head to his heel. At this point, he'll measure over 8 ½ inches long and he'll weigh about 12 ounces. He's as big as a grapefruit!

 

22 Weeks: An Ear of Corn

size of baby week 22

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At 10 inches long, your baby is the length of an ear of corn and weighs 14 ounces. Her eyes are fully formed, but they haven't developed pigment yet.

 

23 Weeks: A Green Onion

size of baby week 23

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Your baby is the length of a green onion, about 11 ¼ inches long, and weighs a pound.

 

24 Weeks: A Leaf of Kale

size of baby week 24

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At slightly over 12 ½ inches long and weighing in around 1 ¼ to 1 ½ pounds, your baby is length of a leaf of kale. He's also starting to develop taste buds.

 

25 Weeks: A Zucchini

size of baby week 25

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Your baby is the length of a zucchini, 13 inches long. She also weighs between 1 ½ and 1 ¾ pounds.

 

26 Weeks: A Coconut

size of baby week 26

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Your baby is slightly over 13 1/3 inches long and weighs 2 pounds, the size of a coconut.

 

27 Weeks: An Acorn Squash

size of baby week 27

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At 13 ¾ inches and 2 ¼ pounds, your little love weighs as much as an acorn squash. He's starting to develop regular sleep and wake cycles.

 

28 Weeks: A Butternut Squash

size of baby week 28

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Your baby is the size of a butternut squash -- about 14 ¼ inches long and 2 ½ pounds.

 

29 Weeks: A Large Cabbage

size of baby week 29

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Your baby now measures over 14 ½ inches and weighs 2 ¾ pounds. She's as big as a large cabbage.

 

30 Weeks: A Large Eggplant

size of baby week 30

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Your baby is the size of a large eggplant (a little over 15 inches and 3 pounds).

 

31 Weeks: A Stalk of Celery

size of baby week 31

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At this point, your baby is about 15 ½ inches long (the length of a celery stalk) and between 3 ½ and 4 pounds. Her skin is pink, and she's really starting to gain weight.

 

32 Weeks: Two Heads of Cauliflower

size of baby week 32

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Your baby is slightly over 16 inches long and weighs between 4 and 4 ½ pounds -- as much as two heads of cauliflower.

 

33 Weeks: A Jicama

size of baby week 33

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The length of a jicama, your little one is now 16 ½ inches long and weighs up to 5 pounds. Meanwhile, you've produced about two pints of amniotic fluid.

 

34 Weeks: A Honeydew Melon

size of baby week 34

Lew Robertson/Stockfood Creative/Getty Images

At around 17 ½ inches long and weighing between 5 and 5 ½ pounds, your baby is the size of a honeydew melon. Your body is getting ready for delivery -- you might even notice colostrum in your breasts.

 

35 Weeks: A Small Spaghetti Squash

size of baby week 35

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Your baby is the weight of a small spaghetti squash -- up to 6 pounds -- and between 17 and 18 inches long.

 

36 Weeks: A Large Chinese Cabbage

size of baby week 36

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You're getting close to delivery day, and your baby is getting ready: he's starting to lose the hair that covered his skin, and he's most likely head down already. He's the length of a large Chinese cabbage, between 17 ½ to 19 inches long and weighing in at 5 ¾ to 6 ¾ pounds.

 

37 Weeks: A Winter Melon

size of baby week 37

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Your baby is 18 inches long and weighs 6 to 7 pounds, the size of a winter melon.

 

38 Weeks: A Pineapple

size of baby week 38

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At this point, your baby is between 17 and 20 inches long and weighs as much as 7 ½ pounds. He's as long as a pineapple.

 

39 Weeks: A Small Watermelon

size of baby week 39

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Your baby weighs as much as a small watermelon, between 6 ½ and 8 pounds. He's also between 18 and 20 ½ inches long.

 

40 Weeks: A Pumpkin

size of baby week 40

Oleksiy Maksymenko/Imagebroker/Getty Images

 

Your baby is ready for delivery, and he's as big as a pumpkin. Of course, the size of babies varies greatly, but he'll probably be between 19 and 21 inches long and between 6 ¾ to 10 pounds. You (both) made it!

Sources: Robin Elise Weiss, author of The Complete Illustrated Pregnancy Companion; The American Pregnancy Association

Read more on your Pregnancy:
Track your pregnancy week by week and learn about what's happening with your body

Signs of labor: how to know it's time for delivery

A freakout-free guide on what to expect after childbirth

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