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    Close up of a baby's hand as they're laying in a crib wearing a sleeping bag

    Our guide to choosing the best sleep bag for your baby

    TOG ratings, size guides, seasonal options — baby sleeping bags have more to think about than you'd expect. Here's the simple version to help you pick the right one.

    Author: Anna | Comfort Category Manager

    Posted on: 10 May, 2022

    Reading time: 5 mins

    Baby sleepbags are a great way to keep your baby safe and comfortable as they snooze. They're available in different sizes and tog ratings for different ages and seasons.

    Read on to learn all about baby sleepbags, and which type is right for your baby.

    What are the benefits of using a baby sleeping bag?

    Lots of parents choose to dress their baby in a sleeping bag instead of using blankets or sheets which can pose a risk of suffocation and overheating. If you do use a lightweight blanket, make sure it's not tucked in higher than their shoulders and that they're in the "feet to foot" position, with their feet at the end of their cot or Moses basket.

    Sleeping bags are basically wearable blankets for babies that keep them comfortable and at a safe temperature as they sleep. They are safer for little ones because there's no need for blankets, so their head remains safely uncovered, reducing the risk of suffocation.

    The other benefits of baby sleeping bags include...

    • They help baby to stay at a constant temperature.
    • Your baby can move around in the bag but still stay covered and cosy.
    • They're really handy for night feeds.
    • They mean that there's no need for additional covers that baby could kick off or get tangled up in.
    • They promote good sleep and become a recognisable part of your little one's bedtime routine.

    a baby wearing a swaddle

    What size sleeping bag should my baby wear?

    Your baby's head shouldn't be able to pass through the neck hole when their sleepbag is fastened. If it can, the sleepbag is too big for them. Remember to check the weight of your child and refer to the chart below.

    Remember, these are recommendations only as all babies are different...

    Sleepwear Size  Baby's Height Baby's Weight
    0-3 Months  up to 62cm 7-13lbs 8oz / 3.2-6.1kg
    3-6 Months  62-68cm 13lbs 8oz -18lbs / 6.1-8.2kg
    6-18 Months  68-86cm 18-25lbs / 8.2-11.3kg
    18-36 Months 86-98cm from 25lb / 11.3kg

     What tog should my baby wear?

    Tog stands for Thermal Overall Grade. It's a measure of warmth, rather than thickness. A product's tog value is determined by a lab test. Basically, the higher the tog rating, the warmer the product.

    The temperature of the room your baby sleeps in will influence the tog that's required. 

    Here's a breakdown of which tog should be worn when...

    Sleep Bag Tog

    Room Temperature
    3.5 Tog Designed for winter months and cold rooms below 16°C / 57°F
    2.5 Tog Designed for year-round use and room temperatures between 16-20°C / 57°F-68°F
    1.0 Tog Designed for warm summer months and room temperatures between 20-24°C / 57°F-75°F
    0.2 Tog Designed for heatwaves, hot weather, and very warm room temperatures above 24°C / 75°F

     What should my baby wear with their sleeping bag?

    Generally, the warmer a room is, the less your baby needs to wear under their sleeping bag. Remember that all babies are different, and you'll soon learn what your little one is comfortable in.

    Your baby shouldn't become too warm in their sleeping bag, as long as you choose the correct tog for the room's temperature and they're not wearing too many layers underneath it.

    If you can, choose a sleep bag with no sleeves or detachable sleeves, and don't use any clothes or bedding that your little one could get tangled up in.

    Signs a baby is too hot can include them...

    • Feeling hot or sweaty to touch on their tummy, neck or back
    • Having damp hair
    • Flushing in the cheeks
    • Increasing their breathing rate

    To monitor their temperature, The Lullaby Trust suggests feeling your baby's chest or the back of their neck (your baby's hands and feet will usually be cooler, which is normal). If your baby's skin is hot or sweaty, remove one or more layers of bedclothes.

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