The Sleep Onesie is a TOG-rated sleep sack alternative, designed to be worn on its own during sleep or with a Romper/PJs underneath for warmth and comfort.
Size Guide
Sleep Onesie
Please use your child's weight and height to find the most appropriate and safe size for them.
Imperial Size Chart
| ergoPouch Size
(same as size) |
Pouch Length (inch) | Chest width (inch) | Child Height (inch) |
|---|---|---|---|
| 6-12M (0-1y) |
29.1" | 10.8" | 26.8 - 33.1" |
| 12-24M (1-2y) |
33.1" | 12" | 29.9 - 36.2" |
| 2-3Y | 34.6" | 12.6" | 36.2 - 39.4" |
| 4-5Y | 38.6" | 13.8" | 42.5 - 45.3" |
| 6-8Y | 43.3" | 15" | 47.2 - 51.2" |
| 8-10Y | 47.2" | 15.7" | 51.2 - 55.1" |
| 10-12Y | 51.2" | 16.5" | 55.1 - 59.1" |
Metric Size Chart
| ergoPouch Size
(same as size) |
Pouch Length (cm) | Chest width (cm) | Child Height (cm) |
|---|---|---|---|
| 6-12M (0-1y) |
74cm | 27.5cm | 68-84cm |
| 12-24M (1-2y) |
84cm | 30.5cm | 76-92cm |
| 2-3Y | 88cm | 32cm | 92-100cm |
| 4-5Y | 98cm | 35cm | 108-115cm |
| 6-8Y | 110cm | 38cm | 120-130cm |
| 8-10Y | 120cm | 40cm | 130-140cm |
| 10-12Y | 130cm | 42cm | 140-150cm |
The Sleep Onesie should be fitted around the neck to avoid your child slipping through. 2.5 TOG and 3.5 TOG Sleep Onesies should not be used in a 5-point harness or car seat for safety reasons.
- Free delivery on orders over $70*
- Estimated dispatch: 22 February 2026
- 30-day returns and exchanges
- Holly E.Verified Buyer2/18/26ReviewingSleep Onesie 3.5 TOG DragonfliesRated 5 out of 5 starsThe best!
I looked for a while for something made of organic cotton and then also stuffed with organic cotton!! This checks all the boxes
- Jenny S.Verified Buyer2/16/26ReviewingSleep Onesie 2.5 TOG Elephant ParadeRated 5 out of 5 starsLove!
Just what my daughter needed! It’s super soft and great quality. My daughter seems to be sleeping better too!
- Sammi B.Verified Buyer2/5/26ReviewingSleep Onesie 3.5 TOG Sweet OrchardRated 5 out of 5 starsPerfect service
My son wears his religiously as our home sees temperatures as low as 14°c. It started to fray quite a bit and I told the company, they sent me a replacement straight away. Great service. I will definitely shop here again
