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Parent guide · tried-and-tested rules of thumb

What should my baby wear?

The simple answer for every temperature – for outdoors, stroller, baby carrier, car, at home and for sleep. With a calculator, charts and the most important safety tips.

In short: dress your baby in one thin layer more than you would wear yourself (layering principle). Check whether it fits at the neck – warm & dry is just right. Choose the temperature and the situation below for a specific recommendation.

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Clothing calculator

Pick the situation, slide the temperature – done.

18°C feels-like temperature
❄️ −10°36° ☀️
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Sleep sack calculator

For sleeping indoors: room temperature → TOG rating.

19°C in the bedroom
12°28°

📏The most important rule of thumb

Babies can't regulate their temperature well in the first months. That's why:

🚶Outdoors: chart by temperature

Guide values for a walk. In the stroller (pram) the same applies (there's no body heat from you), and a footmuff replaces the thick blanket.

TemperatureRecommendation
from 28 °C
very hot
Diaper only or a thin short-sleeve bodysuit · sun hat with neck flap · thin muslin cloth for shade. Avoid the midday sun (11 a.m.–3 p.m.), feed/offer drinks more often.
23–27 °C
warm
Short-sleeve bodysuit · thin trousers or a light romper · sun hat · thin socks.
18–22 °C
mild
Long-sleeve bodysuit · trousers or romper · thin hat · light jacket within reach.
13–17 °C
cool
Long-sleeve bodysuit · sweater + trousers or a warm romper · light jacket · hat · socks.
8–12 °C
cold
Long-sleeve bodysuit · boiled-wool or fleece suit · jacket · hat over the ears · mittens · footmuff in the stroller.
3–7 °C
very cold
Long-sleeve bodysuit + sleepsuit/boiled wool · winter jacket or snowsuit · warm hat · mittens · warm footmuff.
below 3 °C
frost
Warm winter all-in-one · thick hat over the ears · neck scarf (no loose scarf) · thick mittens · sheepskin footmuff. Keep outings short, check cheeks/neck.

👶In the baby carrier

In the carrier your body heat counts as one layer – dress your baby in one layer less than in the stroller. Cover legs and feet extra because they hang out freely. In winter, use a babywearing jacket or carrier cover over both of you instead of a thick jacket for the baby.

⚠️ Keep the airway clear: chin away from the chest, fabric and scarf away from mouth & nose. Always keep your baby in view.

🚗In the car & car seat

Here safety matters more than warmth:

⚠️ No thick or padded jacket and no snowsuit in the car seat. Thick clothing is compressed in a crash – the harness then sits too loosely and the child can be thrown forward (advice from the ADAC, Germany's automobile club). Better: dress thin, fasten the harness snugly, then lay a blanket OVER the fastened harness. The heating warms the car up quickly anyway.

🏠At home: by room temperature

Room temperatureRecommendation
from 24 °CShort-sleeve bodysuit · thin trousers if needed · barefoot or thin socks. Watch for overheating, air the room.
20–23 °CLong-sleeve bodysuit · romper or light trousers · socks.
18–20 °C (ideal)Long-sleeve bodysuit · romper · socks.
below 18 °CLong-sleeve bodysuit · romper + light sweater · socks · thin hat if needed.

🌙For sleep: TOG rating & what goes underneath

A baby sleep sack replaces loose blankets (which don't belong in the crib). The TOG rating tells you how warm the sleep sack is – matched to the room temperature. The sleep sack calculator at the top gives you the right value; here is the chart for reference:

Room temperatureTOG ratingUnder the sleep sack
from 24 °C0.5 TOG (summer)Diaper only or a short-sleeve bodysuit
20–23 °C1.0 TOG (spring/autumn)Short- or long-sleeve bodysuit
16–20 °C2.5 TOG (all year)Long-sleeve bodysuit (+ romper at ~16–18 °C)
below 16 °C3.5 TOG (winter)Long-sleeve bodysuit + sleepsuit
💤 Safe sleep: ideal sleep temperature 16–20 °C. No hat in bed, no loose blankets or pillows. Check for overheating at the chest or neck – not at hands or feet.
HeyFini

By Felix & Merle · parents of Josefine

We built HeyFini out of our own everyday life with a baby. Our recommendations are based on recognised sources (among them the Lullaby Trust for safe sleep and the ADAC, Germany's automobile club, for car-seat safety) and our own experience as parents – more in our story. Last updated: June 2026.

📚More dressing guides

Frequently asked questions

How much should I dress my baby in?

One thin layer more than yourself, using the layering principle. Check the neck – warm and dry is right. Sweaty = too warm, cool = one layer more. Hands/feet aren't suitable for checking.

How do I tell whether it's too warm or too cold?

Feel the back of the neck or the upper back. Warm and dry = all good. Sweaty and hot = overheating, remove a layer. Cool = one layer more.

What should my baby wear in the car seat?

No thick/padded jacket and no snowsuit. Dress thin, fasten the harness snugly and lay a blanket over the fastened harness (ADAC advice).

What should my baby wear in the baby carrier?

One layer less than in the stroller, because your body heat counts. Cover legs and feet extra. Keep the airway clear.

Which TOG rating suits which room temperature?

0.5 TOG from ~24 °C, 1.0 TOG at 20–23 °C, 2.5 TOG at 16–20 °C, 3.5 TOG below 16 °C. 16–20 °C is ideal.

Can I cover the stroller with a blanket?

No – heat builds up underneath (at 26 °C outside up to ~37 °C within 30 min). Use a breathable sun canopy/parasol instead.

Never wonder again – with HeyFini

The HeyFini app does the working-out for you: it uses the current weather at your location and automatically suggests suitable clothing for outdoors, stroller, carrier, car and sleep – plus feeding, sleep & growth. Private in your iCloud.

More about HeyFini

General guidance, not medical advice. Every child feels warmth differently – the neck/chest check is what counts. When in doubt, ask your paediatrician or midwife.