Girls' School Innerwear: Size by Age, Fit and Fabric

Which size fits which age

Children's innerwear here is numbered by waist measurement in centimetres, from 45 upwards. Size 60 means a 60 cm waist. The ages below are what that measurement usually corresponds to, but children of the same age differ by several centimetres, so measure where you can.

To measure, run a tape around the natural waist — above the hip bone, level all the way round, snug but not tight — and round up to the next number. A child measuring 62 cm takes size 65. No tape at home? A length of thread held against a school ruler works just as well. The full size guide covers adult sizes too, since the same bloomer shape runs from 45 all the way to 100.

Bloomer or panty for school?

For girls in a skirt or pinafore uniform, a bloomer — the longer-legged cotton style — is the practical choice. The extra leg means coverage stays put through sitting cross-legged, PE, running and the trip home, and it prevents thigh rubbing during a hot afternoon. Under trousers, a shorter panty is fine.

If you are not sure what separates the two shapes, our guide to bloomer vs panty shows both in one photograph.

Start with the fabric

100% cotton is the sensible daily choice for a school day in this climate: it feels soft against the skin and lets moisture move instead of trapping it. Check the label, then touch the fabric — it should feel smooth, not stiff or scratchy. A cotton-rich blend costs a little less and holds shape slightly longer, but on a hot afternoon in a closed classroom the difference is felt immediately.

Avoid anything with a rough inner seam, a printed logo on the inside, or a stiff waistband label. Those are the three things children actually complain about.

Check the fit while she is moving

Trying a garment on standing still tells you very little. Ask her to sit on the floor, bend forward and walk across the room:

• The waistband should stay put and not roll down when she sits.
• The leg opening should not pull upward or leave a deep mark.
• There should be no constant adjusting. If she is pulling at it within a minute, the size or the cut is wrong.

How many pairs does a school week need?

Plan for the washing cycle rather than the week. For a child at school five days a week, seven to ten pairs is the number that works in most homes:

• Five for school days.
• Two for the weekend.
• Two or three spare for the wash, for a rainy week when nothing dries, and for the set the school asks you to keep in the bag.

Fewer than that and the same pairs are washed and worn constantly, which is what wears out elastic fastest. Buying a slightly larger number of pairs is cheaper over a year than replacing a small rotation twice.

Washing so they last the year

• Wash in cold or warm water, not hot. Heat is what kills elastic.
• Keep new dark colours away from whites for the first few washes.
• Dry in shade rather than harsh sun — strong sun fades dark colours and yellows white.
• Do not wring the waistband. Reshape it gently and hang it to dry.
• Replace a garment when the elastic no longer returns to shape. A loose waistband cannot be fixed by washing, and sizing down to compensate makes the fit worse.

There is more detail in our cotton innerwear care guide.

Babies and toddlers

For the youngest sizes — 45 to 55, roughly one to four years — the checks change slightly. Softness matters more than anything else, because the skin is more sensitive and the garment is worn all day. Look for a flat, covered waistband elastic, seams that lie flat at the inner thigh, and enough room to crawl, climb and be picked up without the leg cutting in.

Toddler innerwear is also washed far more often than anyone plans for, so durability is a fabric question rather than a stitching one: 100% cotton that survives frequent washing without going thin is worth more than a decorative print that does not. Buy in the same rotation logic as above — more pairs, washed gently, last longer than a few pairs washed hard.

Practical school habits

• Choose colours that work under the uniform. Dark colours under dark uniforms; a light neutral under white or cream.
• Write the child's name on the care label if the school keeps spare clothing.
• Keep one spare set in the school bag for younger children.
• Re-measure the waist once a year, before the school year starts. Four centimetres of growth is a full size.

Common questions

What size innerwear should I buy for a 7-year-old?

Size 65 usually fits a 7–8 year old, which is a 65 cm waist. Measure if you can, because waist size varies more than age suggests.

Should school innerwear be a bloomer or a panty?

A bloomer under skirt or pinafore uniforms, because the longer leg keeps coverage through sitting, sports and play. Either works under trousers.

How many pairs should a school-going child have?

Seven to ten. Five for school, two for the weekend, and two or three in the wash or kept spare.