Kids' kigurumi: what age, what size, what safety checks

A kids' kigurumi is a one-piece fleece onesie with an animal or monster hood that children wear in the evening in the living room, for a sleepover or as a costume. The question that comes up before buying is size: which number for a 3-year-old, a 7-year-old, a 12-year-old? The answer comes down to one rule, choose by height, not by age, plus a few safety checks. The examples below come from the shop's product pages: the Star Monster Kigurumi, the Kids' Plush Animal Onesie, the Baby Animal Kigurumi and the Family Fleece Onesie.

A kids' kigurumi: from what age?

From the first few months for a baby style worn during the day, and with no upper age limit after that: sizes go all the way up to adult. What changes with age is the style and how it's used.

• From birth to 4 years: the Baby Animal Kigurumi comes in sizes from 0–6 months to 4 years. Its cuffs fold over to cover the smallest babies' hands, and its zip runs down the front.
• From about 80 to 145 cm: the Kids' Plush Animal Onesie and the Star Monster Kigurumi go from 100 to 140.
• Beyond that: adult sizes take over, with the same Star Monster in S, M, L and XL for those who want to wear the same style as their parents.

For a baby, the kigurumi remains a daytime outfit. Night-time is another matter, covered further down.

What size kids' kigurumi: read the centimetres, not the number

A size number doesn't mean the same thing from one style to another: always look at the range in centimetres on the product page. A “100” covers 80 to 100 cm in the Kids' Plush Animal Onesie, but 85 to 105 cm in the Star Monster Kigurumi. And in the Family Fleece Onesie, the Kids 8 size corresponds to 90 to 105 cm: it isn't a size for 8-year-olds.

Photo: Clément Bucco-Lechat / Wikimedia Commons (CC BY-SA 3.0)

Here are the ranges given in the product descriptions:

The Family Fleece Onesie numbers its kids' sizes differently, with height and weight: 8 (90 to 105 cm, 12 to 17 kg), 10 (105 to 115 cm, 15 to 21 kg), 12 (115 to 125 cm, 21 to 25 kg), 14 (125 to 135 cm, 25 to 29 kg) and 16 (135 to 145 cm, 29 to 33 kg).

So from one style to another, the same height doesn't always land on the same number. A child who is 103 cm tall takes a 110 in the Kids' Plush Animal Onesie (100 to 110 cm), a 100 in the Star Monster Kigurumi (85 to 105 cm) and an 8 in the Family Fleece Onesie (90 to 105 cm).

The Baby Animal Kigurumi works differently: its product page says it fits true to size and is chosen by the child's age (0–6 months, 6–12 months, 12–18 months, 18–24 months, 3 years, 4 years).

How to measure: the child stands barefoot with their back against a wall. Lay a book flat on their head, mark the wall in pencil and measure from the floor to the line. Two children of the same age can be several centimetres apart, which is why “3 years” or “7 years” isn't enough.

Between two sizes, take the larger one, as the product pages advise: the cut is roomy, and children grow. But not two sizes up: trailing legs make children trip on the stairs. If the hem is a little long, turn it up.

Kigurumi for a 12-year-old: when to move to adult sizes

Beyond 140–145 cm, kids' sizes are no longer enough. The 140 stops at 140 cm in the Kids' Plush Animal Onesie and at 145 cm in the Star Monster Kigurumi.

Two options for a tween:

• The Star Monster Kigurumi in S (148 to 157 cm). Its cut is the same from kids' to adult sizes: parents and children can wear exactly the same style.
• The Family Fleece Onesie, in Kids 16 (135 to 145 cm, 29 to 33 kg) or Women S (145 to 155 cm, 33 to 43 kg). Panda, ginger tiger, brown bear, dinosaur or capybara: everyone wears the same animal, each in their own size.

For adult sizes, our guide to choosing the right adult onesie size explains how to take measurements.

Going to the toilet: the detail to check

Before you buy, look at how the kigurumi opens: that's what decides whether a child can go to the toilet on their own. A one-piece that has to come off completely makes things harder for a child who has just been potty trained.

The shop's three kids' kigurumis each have their own solution:

• Star Monster Kigurumi: a zip from the collar to the waist, plus a lower zip “so there's no need to take everything off to go to the toilet”, according to the product page.
• Kids' Plush Animal Onesie: fastens with a zip or buttons depending on the design, with an opening at the back designed for the toilet. Let your child try it at home: a little one can't always reach an opening at the back without help.
• Baby Animal Kigurumi: a zip that runs down the front.

For a kids' sleepover, show them the opening before they leave: they won't have to ask for help in front of their friends.

Can a child sleep in a kigurumi?

Yes, for a child who already sleeps under a duvet, with the hood folded back and lighter bedding. Fleece flannel is warm: fleece plus a winter duvet is often too much.

France's Assurance Maladie advises against piling on layers of clothing so that the child doesn't get too hot, and suggests checking with a hand on the back of the neck that they're comfortable (ameli.fr, “How to put a baby to bed safely”, in French). As for the hood, it stays down at the back: with its ears and horns, it twists when the child turns over.

For a baby, the rule is different. The same Assurance Maladie page says to put babies to sleep on their back, on a firm mattress, in a suitable baby sleeping bag, with no pillow, duvet, blanket or cot bumper, in a room at 18–20 °C; it adds that a duvet can only be used from the age of 3. So the baby kigurumi is worn during the day, with an adult keeping an eye, and not as nightwear. Our article on sleeping in a fleece onesie gives temperature guidelines for older children.

Safety checks: flames, small parts, stairs

Keep a roomy fleece onesie well away from flames. The London Fire Brigade points out that any clothing can catch fire if it comes into contact with a candle, a tealight, a firework or a sparkler, whether it's a costume or not (London Fire Brigade, “Fancy dress costumes”). It recommends battery-operated candles or glow sticks instead of naked flames, and teaching children to “stop, drop and roll” if their clothes catch fire, practising it a few times.

Photo: Arisepeter / Wikimedia Commons (CC BY-SA 4.0)

Three other checks:

1. Small parts. Appliquéd eyes, a padded snout, felt teeth, horns: check the seams regularly, especially for children under 3, and take the onesie off if anything comes loose.
2. Leg length. A trailing hem catches under the foot on the stairs. The slippers shown in the Kids' Plush Animal Onesie photos aren't included: add non-slip slippers or turn the hem up.
3. The hood outdoors, in the evening. A hood that slips over the forehead blocks the view. For trick-or-treating on Halloween night, an adult goes along and the child wears something light-coloured or reflective: our kids' Halloween pyjama ideas cover these rules.

Caring for a kids' kigurumi

Follow each style's label: the instructions aren't the same everywhere. The Star Monster Kigurumi, the Baby Animal Kigurumi and the Family Fleece Onesie are machine washable at 30 °C on a delicate cycle, then air dried. The description of the Kids' Plush Animal Onesie says machine wash on a normal cycle or hand wash, then air dry.

Wash the onesie inside out with the zip done up. The details, fabric softener and tumble dryer included, are in our guide to washing and caring for fleece pyjamas.

In a nutshell

To choose a kids' kigurumi, measure your child and read the centimetres on the product page: the size number varies from one style to another. Take the next size up if in doubt, never two. Check how the onesie opens for the toilet, fold the hood back at night, and keep fleece away from flames. The Kids' Plush Animal Onesie comes as a cat, unicorn, shark, dinosaur or panda, the Star Monster Kigurumi is available from kids' to adult sizes, and the Baby Animal Kigurumi dresses the under-4s. For the whole family in matching outfits, see the Family Fleece Onesie and our article kigurumi: what it is and how to choose one.

Cover photo: Dan Bollinger / Wikimedia Commons (CC BY-SA 4.0)