What is baby size by week?
Each week of pregnancy is often paired with a fruit or vegetable of a similar length. It is a shorthand partners actually remember - “the size of a banana” sticks better than 25.6 cm.
Free Pregnancy Tool
Baby Size by Week
Pick a week to see the comparison, or enter a due date to jump to this week. No account, nothing uploaded.
Don't know the week? Use our Pregnancy Week Calculator to find out.
Enter a due date to select this week's size automatically.
Don't know the due date? Use our Due Date Calculator to find out.
Enter a week between 4 and 40.
WEEK 20
Banana
25.6cm
Baby size chart (weeks 4–40)
| Week | Size of | Length |
|---|---|---|
| Week 4 | Poppy seed | 1–2mm |
| Week 5 | Sesame seed | 2mm |
| Week 6 | Lentil | 4–6mm |
| Week 7 | Blueberry | 1cm |
| Week 8 | Raspberry | 1.6cm |
| Week 9 | Cherry | 2.3cm |
| Week 10 | Strawberry | 3cm |
| Week 11 | Lime | 4.1cm |
| Week 12 | Plum | 5.4cm |
| Week 13 | Lemon | 7.4cm |
| Week 14 | Nectarine | 14.7cm |
| Week 15 | Pear | 16.7cm |
| Week 16 | Avocado | 18.6cm |
| Week 17 | Pomegranate | 20.4cm |
| Week 18 | Sweet potato | 22.2cm |
| Week 19 | Mango | 24cm |
| Week 20 | Banana | 25.6cm |
| Week 21 | Carrot | 26.7cm |
| Week 22 | Papaya | 28cm |
| Week 23 | Coconut | 29cm |
| Week 24 | Corn on the cob | 30cm |
| Week 25 | Cauliflower | 34.6cm |
| Week 26 | Lettuce head | 35.6cm |
| Week 27 | Head of broccoli | 36.6cm |
| Week 28 | Aubergine / eggplant | 37.6cm |
| Week 29 | Butternut squash | 38.6cm |
| Week 30 | Cabbage | 39.9cm |
| Week 31 | Bunch of asparagus | 41.1cm |
| Week 32 | Pineapple | 42.4cm |
| Week 33 | Celery bunch | 43.7cm |
| Week 34 | Cantaloupe melon | 45cm |
| Week 35 | Honeydew melon | 46.2cm |
| Week 36 | Romaine lettuce | 47.4cm |
| Week 37 | Swiss chard bunch | 48.6cm |
| Week 38 | Leek | 49.8cm |
| Week 39 | Watermelon slice | 50.7cm |
| Week 40 | Pumpkin | 51.2cm |
How these sizes are chosen
The comparisons use typical crown-to-rump length early on, then overall length later. They are rounded, familiar objects, not a growth scan. Every pregnancy is different.
Why partners look this up
It is one of the few weekly facts that is easy to share without sounding like you memorised a textbook. Knowing this week's comparison is a small way to stay in the same conversation.
FAQ
Frequently asked questions
How weekly size comparisons work, and what they are (and aren't) measuring.
What size is the baby at 20 weeks?
At week 20 the baby is approximately the size of a banana, about 25.6 cm from head to heel. Week 20 is also the halfway point of pregnancy.
When do baby size comparisons start?
Fruit-and-vegetable size comparisons usually start around week 4, when the embryo is about the size of a poppy seed. Before that, measurements are too small for a useful everyday comparison.
Are baby size comparisons accurate?
They are approximate averages, not a measurement of any one pregnancy. Length can vary, and after the first trimester weight matters more than a fruit comparison. Use them as a memory aid, not a medical reading.
Do I need a due date to use this?
No. Pick any week from 4 to 40. If you do have a due date, you can enter it to jump straight to this week's comparison.
More tools
Pregnancy Week Calculator
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Use tool →Pregnancy Weeks to Months
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Use tool →More from the blog
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Read article →The Simple Pregnancy Timeline Every Partner Should Know
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Read article →Built for dads & partners
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