Baby sleeping bag: how to choose one, which TOG to use and what to wear underneath

The baby sleeping bag has become one of the night-time essentials: your baby stays covered even when they move, there are no loose blankets in the cot and the temperature stays more stable. But choosing one raises questions: what TOG do I need? What size? How much should they wear underneath? In this guide we explain it all.

What is a sleeping bag and why use one?

It is a kind of "wearable blanket" your baby wears to sleep: it covers their body, leaves their arms and head free and fastens with a zip or poppers. Its main advantages are:

• They stay covered: even if they move, they remain covered all night.
• No loose blankets in the cot: loose bedding is one of the things it is recommended to avoid where a baby sleeps.
• A more stable temperature, which helps stop them getting too cold or too hot.
• A sleep routine: putting on the sleeping bag becomes a signal that it is time to sleep.

What is TOG and which should you choose?

TOG is a unit that shows how warm a fabric is: the higher it is, the warmer it keeps you. To choose, what matters is the room temperature, not the season. This is a general guide:

• Above 24 °C: low TOG (around 0.5) or just a light bodysuit.
• Between 20 and 24 °C: medium TOG (around 1).
• Between 16 and 20 °C: high TOG (between 2 and 2.5).

Each manufacturer may have its own chart, so always check the instructions for the sleeping bag you buy. If the room is usually below 20 °C, a 2 TOG sleeping bag like our cotton sleeping bag is a good choice for autumn and winter.

On our website you can check the TOG of each sleeping bag on its product page: scroll down to the product information tabs, open "Product Details" and you will see the TOG line next to the composition and care instructions.

How to dress your baby under the sleeping bag

The sleeping bag replaces the blanket, so they do not need many clothes underneath. As a guide:

• In a cool room (16–20 °C): long-sleeved bodysuit and pyjamas.
• In a mild room (20–24 °C): long-sleeved bodysuit or light pyjamas.
• When it is hot (above 24 °C): just a short-sleeved bodysuit, or even no sleeping bag.

To check whether they are the right temperature, feel the back of their neck or their chest, not their hands or feet, which are usually cooler. If they are sweaty, remove a layer; if they feel cold, add one.

Avoid hats for sleep and do not put blankets or duvets on top of the sleeping bag.

How to choose the size

• The sleeping bag should be snug at the neck and armholes, so your baby cannot slip down inside it.
• At the bottom, it should have room for them to move their legs freely.
• Follow the height and age given by the manufacturer and move up a size when it gets short.

Which fabric is best?

For a baby's skin, the best choice is a natural, breathable fabric such as cotton, which helps regulate temperature and reduces the risk of them sweating too much. Also check that it has a textile certificate, such as OEKO-TEX, and that it is easy to wash, because you will use it every night.

Our 100% cotton sleeping bag is sleeveless, has wadding, is 2 TOG and has a front zip that makes nappy changes easier without waking them up.

Safe sleep tips

• Always put your baby to sleep on their back.
• Use a firm, flat mattress with a snug fitted sheet.
• Nothing loose in the cot: no pillows, cushions, soft toys or blankets.
• Keep the room at a comfortable temperature and avoid overdressing them.
• Use a sleeping bag in their size, without a hood.

Frequently asked questions

From what age can you use a sleeping bag?

From one month old, as long as it is the right size and is snug at the neck and armholes so they cannot slip down inside. Our sleeping bag starts at size S, from 1 to 6 months.

What TOG do I need in winter?

It depends on the room temperature, not the season. If it is between 16 and 20 °C, a high TOG (between 2 and 2.5) is usually suitable.

Can you use the sleeping bag in the pram or car seat?

The sleeping bag is designed for the cot. For the car seat there are car seat footmuffs that let the harness come through the slots.

In short

A good sleeping bag keeps your baby covered all night without loose blankets. Choose the TOG according to the room temperature, adjust the clothes underneath, check their temperature at the back of the neck and pick a size that is snug at the top and roomy at the bottom. And if you get it ready along with your baby's layette, you will have it from the very first weeks.