Tiny seed to giant watermelon: How big your baby is this week

Medically reviewed by Judith Venuti, Ph.D., embryologist

Written by Rebekah Wahlberg | Feb 6, 2025

Collage of various vegetables and fruits

Photo credit: Images generated with Adobe Firefly

Quick summary

During pregnancy, your amazing baby grows from poppy seed to watermelon. Isn't it incredible that something so small can turn your world upside down?

To get a sense of baby size by week, check out our baby fruit size guide comparing your little one's approximate length and weight to those of an array of fruits and vegetables.

How big is my baby?

The next time you walk through the grocery store, spend a few minutes perusing the produce aisle. Comparing your baby to something edible is a practice that goes back centuries. In olden times, people used common agricultural items (like seeds, nuts, and fruits) to estimate the sizes of babies in the womb.

These days, we have more variety – including fruits and veggies from around the globe. BabyCenter's baby fruit size comparisons were the first on the web, started in 1997 by staffers who noticed that parents call babies-to-be "little peanut" or "little bean," so we ran with it.

Just so you know, these fruit and veggie comparisons are just for fun – they're not exact, and healthcare providers don't measure embryos and fetuses this way. If you have any questions or concerns about your baby's growth, talk to your provider.

4 weeks: Your baby is the size of a poppy seed

Your pregnancy may be detectable in a week or so by a home pregnancy test.

Read more about what's happening at 4 weeks pregnant.

5 weeks: Your baby is about the size of a sesame seed

Your baby looks more like a tiny tadpole than a human – for now!

Read more about what's happening at 5 weeks pregnant.

6 weeks: Your baby is about the size of a lentil

Your little lentil is now about 1/4 of an inch long.

Read more about what's happening at 6 weeks pregnant.

7 weeks: Your baby is about the size of a blueberry

Your baby has doubled in size since last week and is now about 1/2 an inch long.

Read more about what's happening at 7 weeks pregnant.

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8 weeks: Your baby is about the size of a raspberry

Your little one is now just over 1/2 an inch long and is constantly moving and shifting.

Read more about what's happening at 8 weeks pregnant.

9 weeks: Your baby is about the size of a grape

Your baby now weighs almost an ounce and is almost 1 inch long. Their eyes are fully formed, but the eyelids will be fused shut until 27 weeks.

Read more about what's happening at 9 weeks pregnant.

10 weeks: Your baby is about the size of a strawberry

Your baby now weighs a little over an ounce and is a little over 1 inch long from head to bottom.

Read more about what's happening at 10 weeks pregnant.

11 weeks: Your baby is about the size of a fig

At just over 1 1/2 inches long from head to bottom, your baby is still teeny-tiny – so while they're already kicking and stretching, you won't feel their acrobatics for another month or two.

Read more about what's happening at 11 weeks pregnant.

12 weeks: Your baby is about the size of a lime

Your lime-sized little one now weighs about 2 ounces and is just over 2 inches long.

Read more about what's happening at 12 weeks pregnant.

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13 weeks: Your baby is about the size of a plum

Your little plum is now about 2 1/2 inches long and weighs about 2 1/2 ounces.

Read more about what's happening at 13 weeks pregnant.

14 weeks: Your baby is about the size of a lemon

Your baby – now weighing more than 3 ounces and measuring almost 6 inches from head to heel – can squint, frown, grimace, pee, and possibly suck their thumb.

You may wonder why this week's length measurement is so much bigger than last week.

Until 13 weeks of pregnancy, babies are measured from the top of their head to their bottom. That's because their legs are curled up against their torso during the few weeks of pregnancy, so they're hard to measure. From here on, you'll see the head-to-heel measurements.

Read more about what's happening at 14 weeks pregnant.

15 weeks: Your baby is about the size of an apple

The future apple of your eye now weighs more than 4 ounces and is about 6 1/2 inches long from head to heel.

Read more about what's happening at 15 weeks pregnant.

16 weeks: Your baby is about the size of an avocado

Your baby now weighs 5 ounces and is 7 inches long.

Read more about what's happening at 16 weeks pregnant.

17 weeks: Your baby is about the size of a turnip

Your little turnip now weighs about 6 1/3 ounces and is roughly 8 inches long.

Read more about what's happening at 17 weeks pregnant.

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18 weeks: Your baby is about the size of a bell pepper

Your baby now weighs almost 8 ounces and is more than 8 1/2 inches long from head to bottom. If you're having a girl, her uterus and fallopian tubes are formed and in place. If you're having a boy, his genitals are noticeable now, but he may hide them from you during an ultrasound.

Read more about what's happening at 18 weeks pregnant.

19 weeks: Your baby is about the size of a pomegranate

Your pomegranate-sized baby now weighs more than 9 1/2 ounces and is roughly 9 1/2 inches long.

Read about your baby's development at 19 weeks.

20 weeks: Your baby is about the length of a banana

Your burgeoning baby now measures about 10 inches from head to heel, and weighs roughly 11 1/2 ounces.

Read more about what's happening at 20 weeks pregnant.

21 weeks: Your baby is about as big as a mango

Your mango-sized cutie is now a little over 10 1/2 inches from head to heel and weighs about 14 ounces.

Read more about what's happening at 21 weeks pregnant.

22 weeks: Your baby is about the size of a sweet potato

At 11 1/2 inches and a little over 1 pound, your baby is starting to look like a miniature newborn as their lips, eyelids, and eyebrows become more distinct.

Read more about what's happening at 22 weeks pregnant.

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23 weeks: Your baby is about the size of a grapefruit

Your baby now weighs about 1 1/4 pounds and is more than a foot long – and if you turn on some tunes and sway to the music, they can feel you dance.

Read more about what's happening at 23 weeks pregnant.

24 weeks: Your baby is about as long as an ear of corn

Your baby is now about 12 1/2 inches long from head to heel and weighs nearly 1 1/2 pounds.

Read more about what's happening at 24 weeks pregnant.

25 weeks: Your baby is about the size of an acorn squash

Your baby now rivals the average acorn squash in weight – about 1 3/4 pounds – and is roughly 13 1/4 inches long from head to heel.

Read more about what's happening at 25 weeks pregnant.

26 weeks: Your baby is about the length of a spaghetti squash

Your baby, now nearly 14 inches from head to heel and roughly 2 pounds, may be able to hear both your voice and the voices of people you talk to.

Read more about what's happening at 26 weeks pregnant.

27 weeks: Your baby is about the size of a head of cauliflower

Your baby is now as hefty as a head of cauliflower, weighing in at about 2 1/3 pounds and measuring roughly 14 1/2 inches.

Read more about what's happening at 27 weeks pregnant.

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28 weeks: Your baby is about the size of a large eggplant

Your baby now weighs about 2 2/3 pounds, is almost 15 inches long from head to heel, and can blink their eyes (which now sport lashes).

Read more about what's happening at 28 weeks pregnant.

29 weeks: Your baby is about the size of a butternut squash

Your baby now weighs more than 3 pounds and is about 15 1/2 inches long.

Read more about what's happening at 29 weeks pregnant.

30 weeks: Your baby is about the size of a large cabbage

Your baby tips the scales this week at almost 3 1/2 pounds and is almost 16 inches long.

Read more about what's happening at 30 weeks pregnant.

31 weeks: Your baby is about the size of a coconut

Your baby now weighs almost 4 pounds and measures about 16 1/2 inches long.

Read more about what's happening at 31 weeks pregnant.

32 weeks: Your baby is about the size of a papaya

Your baby is taking up more and more space in your uterus, weighing in at about 4 1/3 pounds and measuring nearly 17 inches from head to heel.

Read more about what's happening at 32 weeks pregnant.

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33 weeks: Your baby is about the size of a pineapple

Measuring 17 1/3 inches from head to heel and weighing about 4 3/4 pounds, your baby is rapidly losing that wrinkled, alien look, and their bones are hardening.

Read more about what's happening at 33 weeks pregnant.

34 weeks: Your baby is about the size of cantaloupe

Your melon-sized munchkin now weighs about 5 1/4 pounds and is almost 18 inches long.

Read more about what's happening at 34 weeks pregnant.

35 weeks: Your baby is about the size of a honeydew melon

Your baby, now weighing in at 5 3/4 pounds and measuring more than 18 inches long, doesn't have much room to maneuver in your belly.

Read more about what's happening at 35 weeks pregnant.

36 weeks: Your baby is about as long as a head of romaine lettuce

Your not-so-little lettuce now measures more than 18 1/2 inches from head to heel and weighs more than 6 pounds (and is still packing it on at a rate of about an ounce a day).

Read more about what's happening at 36 weeks pregnant.

37 weeks: Your baby is about the length of a bunch of Swiss chard

Your baby measures roughly 19 inches from head to heel and weighs about 6 2/3 pounds.

Read more about what's happening at 37 weeks pregnant.

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38 weeks: Your baby is about the length of a mini watermelon

Your baby is now about 19 1/2 inches long and weighs more than 7 pounds.

Read more about what's happening at 38 weeks pregnant.

39 weeks: Your baby is about the size of a pumpkin

Your precious pumpkin now weighs about 7 1/2 pounds and is nearly 20 inches long from head to heel.

Read more about what's happening at 39 weeks pregnant.

40 weeks: Your baby is about the size of a watermelon

Your baby could arrive any day now, if they aren't here already. The average newborn weighs about 8 pounds and is about 20 inches long.

Read more about what's happening at 40 weeks pregnant.

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Sources

BabyCenter's editorial team is committed to providing the most helpful and trustworthy pregnancy and parenting information in the world. When creating and updating content, we rely on credible sources: respected health organizations, professional groups of doctors and other experts, and published studies in peer-reviewed journals. We believe you should always know the source of the information you're seeing. Learn more about our editorial and medical review policies.

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Rebekah Wahlberg

Rebekah Wahlberg is a senior associate editor and baby name trends specialist at BabyCenter, the world's number one digital parenting resource. She lives in Southern California with her silly dog Booger, where she enjoys hiking, yoga, and watching Netflix when she "should" be reading. Wahlberg is passionate about creating content that helps parents and parents-to-be equip themselves with everything they need to succeed.

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