The Sleep Onesie is a TOG-rated sleeping bag alternative, designed to be worn on its own during sleep or with a Layer/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 £65
- Estimated dispatch: 11 November 2025
- 30 day returns & exchanges
- Becki R.Verified Buyer1 week agoReviewingSleep Onesie 2.5 TOG Fruit SaladRated 5 out of 5 starsPerfect onesie
Bought this for my 2.5 year old who kept kicking off her duvet - she loves the fruit pattern and also how snuggly it is. I think she’s waking up a bit less in the night too! It’s very soft and great that you can fold the feet over if needed.
- Miranda M.Verified Buyer1 week agoReviewingSleep Onesie 2.5 TOG Oatmeal MarleRated 5 out of 5 starsLove Our Onesie Sleeper
We love this sleeper! It is the only one we have found where my son’s legs stay in the leg holes so he can be active while wearing it. It keeps him plenty warm at night as well, but it seems like it breathes well too!
- Aynur A.Verified Buyer2 weeks agoReviewingSleep Onesie 2.5 TOG SageRated 5 out of 5 starsGood quality
Quality very good and comfortable