Size
Bamboo Baby Clothing & Sleep Bag Size Guide
Baby clothing is sized first by weight — not by age — because babies grow at very different rates. Find your child’s current weight on the chart below, then match it to the size row. For sleep bags, you also need the room temperature in mind: pair the weight range with the right TOG rating to keep baby comfortable all night.
1. Sleep Bags
Sized by weight, not age. Pair with the TOG rating below.
| Size | Weight (lbs) | Weight (kg) | Recommended Age | Length (in) | Length (cm) |
|---|---|---|---|---|---|
| Newborn | 5 – 8 | 2 – 3.6 | 0 – 3 months | 18 | 46 |
| Small | 8 – 13 | 3.6 – 5.9 | 3 – 6 months | 22 | 56 |
| Medium | 13 – 20 | 5.9 – 9 | 6 – 12 months | 25 | 64 |
| Large | 20 – 25 | 9 – 11.3 | 12 – 18 months | 28 | 71 |
| X-Large | 25 – 30+ | 11.3 – 13.6+ | 18 – 24 months | 31 | 79 |
If baby is between sizes, size up — a slightly larger bag is safer than one that is too snug around the shoulders and chest.
2. Rompers & One-Piece Sleepwear
Zips and snaps for easy diaper changes.
| Size | Weight (lbs) | Weight (kg) | Recommended Age | Height (in) | Height (cm) |
|---|---|---|---|---|---|
| Newborn | 5 – 8 | 2 – 3.6 | 0 – 1 month | 18 – 21 | 46 – 53 |
| 0 – 3M | 8 – 12 | 3.6 – 5.4 | 0 – 3 months | 21 – 23 | 53 – 58 |
| 3 – 6M | 12 – 16 | 5.4 – 7.3 | 3 – 6 months | 23 – 25 | 58 – 64 |
| 6 – 9M | 16 – 20 | 7.3 – 9 | 6 – 9 months | 25 – 27 | 64 – 69 |
| 9 – 12M | 20 – 24 | 9 – 10.9 | 9 – 12 months | 27 – 29 | 69 – 74 |
| 12 – 18M | 24 – 28 | 10.9 – 12.7 | 12 – 18 months | 29 – 31 | 74 – 79 |
| 18 – 24M | 28 – 32 | 12.7 – 14.5 | 18 – 24 months | 31 – 33 | 79 – 84 |
Bamboo fabric has natural stretch. If your baby is between sizes, the smaller size will still fit comfortably and last a full season.
3. Tops & Long-Sleeve Onesies
Same weight sizing as rompers. Use for layering.
| Size | Weight (lbs) | Weight (kg) | Recommended Age | Chest (in) | Chest (cm) |
|---|---|---|---|---|---|
| Newborn | 5 – 8 | 2 – 3.6 | 0 – 1 month | 14 – 15 | 36 – 38 |
| 0 – 3M | 8 – 12 | 3.6 – 5.4 | 0 – 3 months | 15 – 16 | 38 – 41 |
| 3 – 6M | 12 – 16 | 5.4 – 7.3 | 3 – 6 months | 16 – 17 | 41 – 43 |
| 6 – 9M | 16 – 20 | 7.3 – 9 | 6 – 9 months | 17 – 18 | 43 – 46 |
| 9 – 12M | 20 – 24 | 9 – 10.9 | 9 – 12 months | 18 – 19 | 46 – 48 |
| 12 – 18M | 24 – 28 | 10.9 – 12.7 | 12 – 18 months | 19 – 20 | 48 – 51 |
| 18 – 24M | 28 – 32 | 12.7 – 14.5 | 18 – 24 months | 20 – 21 | 51 – 53 |
4. Pants & Leggings
Match by weight. Elastic waistbands have plenty of give.
| Size | Weight (lbs) | Weight (kg) | Recommended Age | Waist (in) | Waist (cm) |
|---|---|---|---|---|---|
| Newborn | 5 – 8 | 2 – 3.6 | 0 – 1 month | 13 – 14 | 33 – 36 |
| 0 – 3M | 8 – 12 | 3.6 – 5.4 | 0 – 3 months | 14 – 15 | 36 – 38 |
| 3 – 6M | 12 – 16 | 5.4 – 7.3 | 3 – 6 months | 15 – 16 | 38 – 41 |
| 6 – 9M | 16 – 20 | 7.3 – 9 | 6 – 9 months | 16 – 17 | 41 – 43 |
| 9 – 12M | 20 – 24 | 9 – 10.9 | 9 – 12 months | 17 – 18 | 43 – 46 |
| 12 – 18M | 24 – 28 | 10.9 – 12.7 | 12 – 18 months | 18 – 19 | 46 – 48 |
| 18 – 24M | 28 – 32 | 12.7 – 14.5 | 18 – 24 months | 19 – 20 | 48 – 51 |
5. Toddler & Kids' Pajamas
Sizes 2T through 5.
| Size | Weight (lbs) | Weight (kg) | Recommended Age | Height (in) | Height (cm) |
|---|---|---|---|---|---|
| 2T | 28 – 32 | 12.7 – 14.5 | 2 years | 32 – 34 | 81 – 86 |
| 3T | 32 – 36 | 14.5 – 16.3 | 3 years | 34 – 37 | 86 – 94 |
| 4T | 36 – 40 | 16.3 – 18 | 4 years | 37 – 40 | 94 – 102 |
| 5 | 40 – 45 | 18 – 20 | 5 years | 40 – 43 | 102 – 109 |
6. Beanies & Headwear
Bamboo knit — stretches to fit.
| Size | Recommended Age | Head Circumference (in) | Head Circumference (cm) |
|---|---|---|---|
| Newborn | 0 – 3 months | 13 – 14 | 33 – 36 |
| 0 – 6M | 0 – 6 months | 14 – 16 | 36 – 41 |
| 6 – 12M | 6 – 12 months | 16 – 18 | 41 – 46 |
| 12 – 24M | 12 – 24 months | 18 – 19.5 | 46 – 49 |
| 2T+ | 2 + years | 19 – 21 | 49 – 53 |
Measure around the forehead, just above the ears and across the widest part at the back of the head.
7. TOG Rating Guide
Pick a TOG to match your nursery temperature.
| TOG | Weight | Room Temp. (°F) | Room Temp. (°C) | Best For |
|---|---|---|---|---|
| 0.5 | Lightweight | 74 – 78 | 23 – 26 | Warm summer nights |
| 1.0 | Light | 69 – 73 | 21 – 23 | Mild weather, spring & early autumn |
| 2.5 | Mid-weight | 61 – 68 | 16 – 20 | Cool autumn & spring nights |
| 3.5 | Plush quilted | 54 – 60 | 12 – 15 | Cold winter nights |
A higher TOG is not always warmer for baby — choose the lowest TOG that keeps baby comfortable in your nursery. Overheating is a known risk factor for safe sleep.
8. How to Measure Your Baby
Three quick steps for an accurate fit.
1. Weigh Baby
Weigh your baby in pounds or kilograms on a digital scale. Use the most recent weight — size is based on weight, not age.
2. Measure Height
Lay baby flat against a wall or measuring mat. Measure from the top of the head to the heel of the foot with legs stretched out.
3. Match the Charts
Find the row on each chart whose weight and height both fit. If they fall between two sizes, prefer the larger size for sleepwear, the smaller size for clothing.
Sleep Bag in The Very Hungry...
The Very Hungry Caterpillar™ and Friends
/
S
Regular price
$16.50
Regular price
$55
Sale price
$16.50
Unit price
per
Sleep Bag in The Very Hungry...
The Very Hungry Caterpillar™ and Friends
/
S
Regular price
$16.50
Regular price
$55
Sale price
$16.50
Unit price
per