TOG Value: what does it mean and which one do you need?
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The tog rating of a baby sleeping bag indicates how much heat the fabric retains. It helps you estimate whether your baby can sleep comfortably at a certain room temperature. However, this tog rating often raises doubts, especially in the first few months.
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What are these values?
The tog rating of a baby sleeping bag is a measure of thermal insulation. The higher the tog rating, the better the fabric retains heat. This means that a sleeping bag with 3.5 tog is warmer than one with 0.5 tog.
Tog stands for Thermal Overall Grade. It's not a measure of thickness, but rather how much heat loss the fabric blocks. That difference is important. A sleeping bag can feel thin and still be quite warm, depending on the material.
In short: the tog rating tells you how much heat a sleeping bag retains, not how thick it looks.
Why is the tog value important?
Babies can't regulate their body temperature well in the first few months. Their thermoregulation develops gradually. This makes them dependent on their environment and what they wear while sleeping.
In practice, I often see that you primarily consider the season. Summer means thin, winter means thick. But the temperature inside a house can vary considerably. A well-insulated house in January can be warmer than a bedroom in April.
Sleep, temperature, and regulation are all interrelated. If your baby is too warm, it can cause restlessness or sweating. If your baby is too cold, it can also affect how deeply or restfully they sleep. This process doesn't happen in isolation.
What role does room temperature play?
Room temperature is actually the foundation of everything. In the Netherlands, VeiligheidNL advises a bedroom temperature of 16 to 18 degrees Celsius. A baby usually feels most comfortable in this range, provided they are dressed appropriately.
However, that temperature isn't always stable. Many parents notice that the room is warmer in the evening than in the early morning. Especially in attic rooms or in well-insulated new houses, the temperature can fluctuate considerably.
A simple room thermometer can help provide insight. Not for obsessive checking, but to understand what happens at night. Because when the room is 22 degrees instead of 18, that requires a different tog rating and fewer layers.
Confusion often arises from thinking in terms of seasons. In winter, you automatically choose a warm sleeping bag. In summer, a thin one. But the temperature in the bedroom doesn't always follow the seasons. A well-insulated house can be warmer than expected in January. And a crisp spring day can actually result in a cooler bedroom than you anticipated.
If you only look at the calendar and not at the actual temperature in the room, your baby may be too warm or too cool without realizing it.
By taking room temperature into account in your choice, you make decisions based on what actually happens in the room where your baby sleeps.
This helps you as a parent to make choices based on observation, not just on general advice.
What tog value do you need?
The correct tog value depends mainly on the room temperature.
Room temperature | Sleeping bag | What your baby wears underneath |
Below 16 °C | 3 tog | long sleeved bodysuit and pyjamas |
16 to 17 °C | 2.5 tog | long sleeved bodysuit and pyjamas |
18 to 19 °C | 2.5 tog | sleeveless bodysuit and a long sleeved top |
20 to 21 °C | 1 tog | long sleeved bodysuit |
22 to 23 °C | 1 tog | short sleeved bodysuit |
Above 23 °C | 0.5 tog | sleeveless bodysuit |
These are guidelines, not hard and fast rules. Every baby reacts differently to temperature. Some get warm faster, while others get cold faster. This difference is normal and part of their development.
In my work, I regularly see parents dress their babies a little warmer out of fear they'll get cold. That reflex is understandable. Cold feels vulnerable, and as a parent, you want to protect them.
At the same time, a baby can usually handle being a little too cool better than too warm within a safe temperature range. When a baby gets too warm, heat can build up in their body. This is called overheating. Because babies don't yet regulate their own temperature effectively, they have more difficulty dissipating excess heat. Therefore, choosing a TOG rating isn't just about comfort; it's also about supporting safe temperature regulation.
And yet, it's sometimes difficult to gauge how warm your baby really is. Signals can be confusing. So, when in doubt, the saying goes: measuring is knowing. A thermometer gives you a more objective picture than just feeling.
This knowledge helps you, as a parent, understand what's normal and how their body and their environment interact. This way, trust grows step by step.
What types of baby sleeping bags are there?
Summer sleeping bags usually have a low tog rating and are made of lightweight, breathable fabrics like cotton. They are designed for warmer rooms.
Winter sleeping bags have a higher tog rating and often contain a lining or thicker fabric to better retain heat.
There are also four-season sleeping bags with removable layers, allowing you to adjust the tog rating to the room temperature.
And yet, no sleeping bag alone is enough information. The combination with a romper, pajamas, and the bedroom temperature makes all the difference.
When is extra attention needed?
If your baby regularly feels clammy, sweats profusely around the neck, or feels cold on the torso, it can be helpful to have a professional check them. Sometimes other factors play a role, such as low birth weight or prematurity.
If you have any lingering doubts, you can always discuss them with youth healthcare or maternity care. Not because there's anything inherently wrong, but because looking at things together can provide peace of mind.
Frequently asked questions about tog value
1. What exactly does the tog value of a baby sleeping bag mean?
The tog rating of a baby sleeping bag indicates how much heat a sleeping bag retains. The higher the tog rating, the better the fabric insulates. It therefore indicates the thermal insulation, not the appearance of the sleeping bag's thickness. A thin sleeping bag can still have a higher insulation value than you expect.
2. What tog rating baby sleeping bag do I need at 18 degrees?
At a room temperature around 18 degrees Celsius, a 2.5 tog sleeping bag is usually used. This fits within the Dutch recommended bedroom temperature of 16 to 18 degrees Celsius. However, this remains a guideline. The combination of clothing layers and how quickly your baby warms up also plays a role.
3. Is it dangerous if my baby is too hot?
A baby can't handle too much heat as well as being slightly too cool within a safe range. When a baby gets too warm, heat can build up in the body. This is called overheating. Because babies don't yet regulate their own temperature effectively, they have more difficulty releasing excess heat. Therefore, it's important to prevent overheating without causing anxiety.
4. How do I know if my baby is too hot or too cold?
External signals can sometimes be confusing. Cold hands don't automatically mean your baby is cold. If you're unsure about their body temperature, the saying goes: measuring is knowing. A thermometer gives you a more objective indication than just feeling.
5. Do I need to adjust the tog value per season?
Not by season, but by room temperature. Many parents automatically think of summer and winter, but the actual temperature in the bedroom is decisive. A well-insulated house can be warmer than expected in winter. Therefore, it helps to make the room temperature a key factor in your choice.
6. What if I am unsure about the correct tog value?
Doubts are common, especially in the first few months. You're still getting to know your baby. It helps to calmly consider the room temperature, the chosen tog rating, and the layers of clothing. If you still have doubts or are concerned about temperature regulation, it can be helpful to discuss this with your child health care provider.
Peace and confidence surrounding the tog value
The tog rating of a baby sleeping bag is a helpful guide. It helps you make an estimate, but it's not a replacement for your own observations.
Your baby is gradually learning to better regulate their body. Variation is normal. Small adjustments are part of the parenting process.
Perhaps in the end it's less about the exact TOG value and more about learning to look at your baby.
Love,
Bobby
Sources
Written by Bobby, maternity nurse at Bobby Kraamzorg. Last updated: September 2026.