How Big Is My Baby – Baby Size By Week
As your baby is growing inside your belly, it’s completely natural to wonder what is going on in there! How is he/she developing, and more specifically – how big is my baby this week? To help you figure it out, we’re using a Fetal Growth Chart with fruits and vegetables to describe the approximate size of your baby week by week.
Why? Because it is easier to imagine the size of your baby if there is something common like fruits and vegetables to compare it with.
Just think. In 40 weeks, your baby will grow from the size of a sesame seed to the size of a jackfruit. It’s truly amazing! Here’s how it happens:
Baby Size By Week 5: Sesame Seed
- Your baby is about the size of a sesame seed and 0.13 inches in size.
- Your baby is looking more like a tiny tadpole than a human being.
- By week five of your pregnancy, the first body segments appear. This will eventually form the primitive spine, brain, and spinal cord.
Baby Size By Week 6: Sweet Pea
- By six weeks, your baby is about the size of a sweet pea, and 0.25 inches in size.
- Your baby’s heart, blood circulation, and digestive tract take shape.
- The embryo is a node approximately 0.196 of an inch long (0.5cm).
- The head is one-third of the total length.
Baby Size By Week 7: Blueberry
- Your baby has doubled in size since last week and is about the size of a blueberry, 0.51 inches big.
- Your baby’s heart starts to pump blood.
- Limb buds appear.
- Also, major divisions of the brain can now be discerned.
Baby Size By Week 8: Raspberry
- Your baby is now about the size of a raspberry, weighs approximately 0.04 ounces and is 0.63 inches big.
- The fetus is constantly moving and shifting.
- Your baby’s eyes begin to take shape.
- External ears are developing from skin folds.
- The exchange of nutrients and waste matter begins through the placenta.
Baby Size By Week 9: Grape
- Your baby is around the size of a grape, 0.9 inches big and weighs approximately 0.07 ounces.
- Your baby’s development is proceeding rapidly.
- Your baby’s face is now complete with eyes, nose, lips, and tongue.
- Tiny bones and muscles appear beneath the thin skin.
Baby Size By Week 10: Prune
- Your baby is now the same size as a prune, 1.22 inches big and weighs approximately 0.14 ounces.
- Once the organs are formed, you now have a fetus. Congratulations!
- Your baby’s tiny heart is beating about 120-160 beats a minute.
Baby Size By Week 11: Lime
- Your baby, now about the size of a lime, is 1.61 inches in size and weighs approximately 0.25 ounces.
- Your baby’s genitals are now well defined.
- Eyelids finish forming and seal shut.
Baby Size By Week 12: Plum
- Your baby is around the same size of a plum, approximately weighing 0.49 ounces and 2.13 inches big.
- Your baby’s blood and bone cells form.
- The first movements start. You may not be able to feel it just yet.
Baby Size By Week 13: Peach
- By week thirteen, your baby is now as big as a peach, weighing around 0.81 ounces and 2.91 inches in size.
- Your baby’s organs begin to function.
- The pancreas starts producing insulin and the kidneys are now producing urine.
Baby Size by Week 14: Lemon
- Your baby is about the size of a lemon, 3.9 inches big and weighs approximately 1.52 ounces.
- The swallowing reflex has been mastered as your baby sucks its thumb while floating weightlessly in the amniotic fluid.
- Your baby’s lungs have taken shape and primitive breathing motions begin.
Baby Size by Week 15: Apple
- Your baby by week fifteen is around the same size as an apple, 4.0 inches big and weighs approximately 2.5 ounces.
- Your baby can sense light, even though the eyelids are sealed closed.
- Your baby is now able to move all joints and limbs.
Baby Size by Week 16: Avocado
- Your baby is now as big as an avocado, weighs approximately 3.53 ounces and 4.6 inches in size.
- The musculoskeletal system has matured.
- Blood vessels are developing rapidly.
- The nervous system starts to exercise some control over the body.
Baby Size by Week 17: Pear
- Your baby is about the size of a pear, approximately 4.94 ounces in weight and 5.12 inches big.
- Your baby can now kick against the amniotic sac wall.
Baby Size by Week 18: Sweet Potato
- At this time, baby is as big as a sweet potato, is 5.6 inches in size and approximately 6.7 ounces in weight.
- Your baby is a lot more active and you may finally feel your baby move.
Baby Size by Week 19: Mango
- By week nineteen, your baby is now the size of a mango, 6.02 inches big and weighs approximately 8.5 ounces.
- All of your baby’s organs and structures have been formed and a period of simple growth begins.
- Your baby’s heartbeat can now be heard with a fetoscope.
- The placenta starts producing the hormone estrogen.
Baby Size by Week 20: Banana
- Your baby is as big as a banana, 6.5 inches in size and approximately 10.2 ounces in weight.
- An oily coating protects your baby.
- Fine hair covers your baby’s body and keeps the oil on the skin.
Baby Size by Week 21: Pomegranate
- Your baby by week twenty-one is around the same size as a pomegranate, weighs approximately 12.7 ounces, and 10.51 inches big.
- Your baby’s eyebrows, eyelashes, and head hair develop.
Baby Size by Week 22: Papaya
- Your baby is now the size of a papaya, weighs approximately 12.7 to 20.8 ounces and around 10.5 to 11.8 inches in size.
- Your baby is following a regular schedule of sleeping, turning, sucking and kicking, and has settled upon a favorite position within the uterus.
Baby Size by Week 23: Grapefruit
- Your baby is about the size of a grapefruit, around 10.5 to 11.8 inches big and approximately 12.7 to 20.8 ounces in weight.
- Your baby is now looking to increase weight and is likely to gain 2 pounds over the next month. Almost double its weight now.
Baby Size by Week 24: Cantaloupe
- By week twenty-four, your baby is the same size as a cantaloupe, around 10.5 to 11.8 inches big and weighs approximately 12.7 to 20.8 ounces.
- Your baby’s skeleton is developing rapidly as the bone-forming cells increase their activity.
Baby Size by Week 25: Cauliflower
- Your baby is around the size of a cauliflower, approximately 1.5 to 2.5 pounds in weight and around 13.6 to 14.8 inches in size.
- Your baby’s eyelids begin to open and close. Yeah!
Baby Size by Week 26: Lettuce
- Your baby is as big as a lettuce, weighs approximately 1.5 to 2.5 pounds and around 13.6 to 14.8 inches big.
Baby Size by Week 27: Rutabaga
- Your baby, now the size of a rutabaga, is around 13.6 to 14.8 inches in size and weighs approximately 1.5 to 2.5 pounds.
- Your baby’s hearing is maturing and may be able to start recognizing familiar voices or sounds but hearing is still distorted by a coating over the ears called vernix.
Baby Size by Week 28: Eggplant
- Your baby in week twenty-eight is about the size of an eggplant, around 13.6 to 14.8 inches big and weighs approximately 1.5 to 2.5 pounds.
- To a certain extent, your baby can now breathe, swallow and regulate body temperature. However, this still depends greatly upon maternal support.
Baby Size by Week 29: Acorn Squash
- Your baby is now as big as an acorn squash, around 15.2 to 16.7 inches in size and approximately 2.5 to 3.8 pounds in weight.
- So that your baby can function independently at birth, a substance called surfactant forms in the lungs.
- Your baby’s respiratory movements can be detected by ultra-sound.
Baby Size by Week 30: Cucumber
- Your baby is the size of a cucumber, around 15.2 to 16.7 inches big and weighs approximately 2.5 to 3.8 pounds.
- Your baby is now two-thirds of his or her birth size.
- Your baby’s skin is changing from being quite transparent to opaque and is very wrinkled.
Baby Size by Week 31: Pineapple
- By week thirty-one, your baby is the size of a pineapple, approximately 2.5 to 3.8 pounds in weight and around 15.2 to 16.7 inches in size.
- Your baby is now starting to get into a sleeping pattern and having longer stretches of sleep.
Baby Size by Week 32: Squash
- Your baby, now the size of a squash, is around 15.2 to 16.7 inches big and weighs approximately 2.5 to 3.8 pounds.
- Fat deposits are building up underneath the skin to insulate your baby against the sudden change in the temperature at birth.
Baby Size by Week 33: Durian
- Your baby is as big as a durian, around 17.2 to 18.7 inches in size and approximately 4.2 to 5.8 pounds in weight.
- The digestive tract and the lungs are now almost fully matured.
- Your baby’s skin becomes less red and wrinkled.
Baby Size by Week 34: Butternut Squash
- Your baby in week 34 is about the size of a butternut squash, around 17.2 to 18.7 big and weighs approximately 4.2 to 5.8 pounds.
- Your baby’s activity might make you feel tired and uncomfortable and your sleeping may be more disturbed.
Baby Size by Week 35: Coconut
- Your baby is the size of a coconut, approximately weighing 4.2 to 5.8 pounds and around 17.2 to 18.7 inches big.
- Virtually your entire uterus is now occupied by your baby.
- The lack of space restricts your baby’s activity.
Baby Size by Week 36: Honeydew Melon
- Your baby is now about the size of a honeydew melon, weighs approximately 4.2 to 5.8 pounds and around 17.2 to 18.7 inches in size.
- Your baby is very close to being ready for life outside the womb.
- Your baby’s most vital organs are matured.
Baby Size by Week 37: Wintermelon
- Your baby is as big as a winter melon, around 18.9 to 20.9 inches in size and weighs approximately 6.2 to 9.2 pounds.
- Nearly fully grown.
- Your baby is technically “Early Term” – with excellent chances if born now. However, as long as everything is going well, the womb is still the best place for baby as he or she continues developing.
- Your baby is still growing about an ounce a day.
- Your baby’s lungs, liver, and brain are still developing.
Baby Size by Week 38: Pumpkin
- By week thirty-eight, your baby is the size of a pumpkin, around 18.9 to 20.9 inches big and weighs approximately 6.2 to 9.2 pounds.
- Week thirty-eight is still technically “Early Term” as your baby continues to increase in weight and his or her lungs, liver, and brain continue developing.
- If your baby arrives now, he or she should be fine but this last bit of growth is good for the baby.
Baby Size by Week 39: Watermelon
- Your baby is about the size of a watermelon, around 18.9 to 20.9 inches in size, and approximately 6.2 to 9.2 pounds in weight.
- Your baby is officially “Full Term” and ready to be born at any time.
- Your baby’s weight gain continues – though at a slower rate.
Baby Size by Week 40: Jackfruit
- Your baby, now the size of a jackfruit, is around 18.9 to 20.9 inches big and weighs approximately 6.2 to 9.2 pounds.
- Over the last few weeks, as your baby has gained weight, his or her skin has fleshed out and lost its wrinkly appearance.
Fetal Growth Chart: Track Your Baby’s Growth Week By Week
Use a fetal growth chart!
A fetal growth chart is basically just a chart that tracks the approximate growth of average babies from week to week during your pregnancy. It will show your pregnancy by week, (the gestational age), and the size and weight of the fetus. Print a free copy, or get a poster in black or white!
