What TOG does my baby need?
TOG (thermal overall grade) measures how much warmth a fabric holds in – the higher the number, the warmer it is. Cotton and polyester sleeping bags usually carry a tested TOG rating. Our Merino sleepwear isn’t TOG-tested, so we give a TOG equivalent for each layer instead: a rough guide to warmth, not a tested rating.
Quick guide: Merino layer by room temperature
Merino layer |
Room temperature |
TOG equivalent |
200gsm Merino |
20–26°C (68–79°F) |
≈1–1.5 |
250gsm Thermal |
18–24°C (64–75°F) |
≈1.5–2 |
Fleece |
16–24°C (61–75°F) |
≈2–2.5 |
Knitted |
14–22°C (57–72°F) |
≈3–3.5 |
Warmest |
12–20°C (54–68°F) |
≈3.5–4 |
These TOG figures are equivalents, not tested ratings, and the guide is only a starting point: every child is different. See the full temperature guide (also in °F).
What to wear underneath (0–12 months)
From our temperature guide for babies 0–12 months:
Room temperature |
Outer layer |
Underneath |
24–26°C |
— |
200gsm onesie |
22–23°C |
— |
200gsm singlet + 200gsm onesie |
20–21°C |
Fleece sleepsuit (≈2–2.5 TOG) |
200gsm singlet |
18–19°C |
Fleece sleepsuit (≈2–2.5 TOG) |
200gsm onesie |
16–17°C |
Fleece sleepsuit (≈2–2.5 TOG) |
200gsm singlet + 200gsm onesie |
14–15°C |
Knitted sleepsuit (≈3–3.5 TOG) |
200gsm singlet + 250gsm thermal onesie |
12–13°C |
Knitted sleepsuit (≈3–3.5 TOG) |
200gsm singlet + 250gsm thermal onesie |
10–12°C |
Knitted sleepsuit + fleece sleeping bag |
200gsm singlet + 250gsm thermal onesie |
How to check your baby isn’t too hot or cold
Feel your child’s chest or the back of their neck. It should feel warm and dry, not hot or sweaty. Cold hands and feet are normal and aren’t a good guide on their own.
Why Merino behaves differently
Merino breathes and moves moisture away from the skin, so it helps your baby stay comfortable as their temperature changes overnight – warm when the room cools in the early morning, without trapping heat and sweat the way synthetic fill can. You still need to match the layers to the room, which is why the guide above gives a TOG equivalent for every layer.
Because Merino copes with a wider range of temperatures, one Merino sleeping bag or sleepsuit can be used across more of the year by changing the layers underneath, rather than buying a different TOG for every season.
Nature is quite remarkable. Our wool is 100% Australian Merino, and when you think of the sheep living in the fluctuating Australian environment, they survive and thrive thanks to wearing their own little micro-environments, living comfortably and consuming nothing but water and grass. Merino wool isn’t about tog ratings; it’s about the course of nature.
Safe sleep basics
For babies under 12 months, keep the cot free of loose bedding, pillows and toys. Always place your baby on their back with their face and head uncovered. See Red Nose safe sleep advice.