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 height to find the most appropriate and safe size for them. 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.
| ergoPouch size | 6-12M | 12-24M | 2-3Y | 4-5Y | 6-8Y | 8-10Y | 10-12Y |
|---|---|---|---|---|---|---|---|
| Same as size | 0-1y | 1-2y | 2-3y | 4-5y | 6-8y | 8-10y | 10-12y |
| Pouch length (cm/inch) | 74cm / 29.1" | 84cm / 33.1" | 88cm / 34.6" | 98cm / 38.6" | 110cm / 43.3" | 120cm / 47.2" | 130cm / 51.2" |
| Chest width (cm/inch) | 27.5cm / 10.8" | 30.5cm / 12" | 32cm / 12.6" | 35cm / 13.8" | 38cm / 15" | 40cm / 15.7" | 42cm / 16.5" |
| Child height (cm/inch) | 68-84cm / 26.8 - 33.1" | 76-92cm / 29.9 - 36.2" | 92-100cm / 36.2 - 39.4" | 108-115cm / 42.5 - 45.3" | 120-130cm / 47.2 - 51.2" | 130-140cm / 51.2 - 55.1" | 140-150cm / 55.1 - 59.1" |
- Free delivery on orders over $70*
- Estimated dispatch: 19 July 2025
- 30 day returns and exchanges for full priced products
- Phaedra W.Verified Buyer7/15/25ReviewingSleep Onesie 3.5 TOG Bon AppetitRated 5 out of 5 starsFantastic product
This is the third suit I have bought for my children...from newborn to a 3 year old our whole family has loved it as we have grown over the years.
- Esther C.Verified Buyer7/14/25ReviewingSleep Onesie 2.5 TOG DragonfliesRated 5 out of 5 starsCosy
Our four year old who kicks off the blanket sleeps through the night thanks to this cosy onesie: no more waking up because he is cold! Thank you.
- Heather W.Verified Buyer7/8/25ReviewingSleep Onesie 3.5 TOG Petit PretzelRated 5 out of 5 stars5 stars
Super warm and comfy. My 3 year old sleeps through with this 3.5 tog sleeping bag. Love it!