Most of us buy school trousers by age. It is the only number on the label, so it is the number we reach for. Then the first week of term arrives and the waistband is digging in, or the hems are dragging along the playground, or your child is quietly hitching them up every ten minutes.

Age is a starting point. It is not a measurement. A nine year old can have a 24 inch waist or a 30 inch waist, and both are completely normal.

This guide explains the six trouser fits we stock, what each one is actually for, and how to work out which one your child needs before you order.

Start with two numbers

Before you look at a single product page, measure your child. Two measurements do almost all the work.

Waist. Measure around the natural waistline, which sits just above the hip bone and usually where your child naturally bends. Keep the tape snug but not tight. If you can slide two fingers underneath, that is about right.

Inside leg. Measure from the top of the inner thigh down to the ankle bone, with your child standing straight and wearing school shoes if you can. Shoes matter more than people expect, because a chunky sole can add most of an inch.

Write both numbers down. Every fit below is chosen using them.

The six fits at a glance

Each fit, and who it is for

Here is the actual size ladder on our plus size eco school trouser, so you can compare it against the numbers you just wrote down.

Sizes shown are those currently listed on that product. Always check the dropdown on the page itself, since availability moves quickly through August.

Parents buy these for three quite different reasons.

The first is reception and infant classes, where a child who cannot manage a button independently will need help every single time they use the toilet, and often will not ask for it.

The second is comfort at the waist. Elastic moves with the child, so it does not dig in when they sit cross legged on the carpet for an hour.

The third is the one nobody talks about openly. Children with dyspraxia, reduced fine motor control, sensory sensitivity or additional needs frequently find fastenings genuinely difficult, and a trouser with none at all removes the problem rather than working around it. If that is why you are here, this is the fit you want, and you do not need to explain yourself to anyone.

Full elastic is available in both regular and sturdy cuts, so you are not choosing between comfort at the waist and the right shape.

When the waist and the leg disagree

This is the situation the age label handles worst. The waist that fits comes attached to a leg that is two or three inches too long, and shortening a school trouser properly is not a five minute job at the kitchen table.

That last point is a real trade off and we would rather say it plainly than bury it. If you are at all unsure of the inside leg measurement, order the unaltered trouser first, check it on your child, and add the alteration on a second pair once you know the number.

A worked example

Say your son is nine. The age nine trouser in the regular range does not fasten. You go up to age eleven, it fastens comfortably, and now the hem is folded over twice.

What has happened is that his waist is running about two sizes ahead of his height. Sizing up by age solved the waist and created a leg problem, because in a regular cut the two are locked together.

The answer is sturdy fit at the waist measurement you took, not the age. From the table above, a 30 inch waist in sturdy fit comes with a 26 inch inside leg rather than the 28 inches you would have inherited by sizing up. If 26 is still long for him, the shortening option closes the gap.

Common questions

What is the difference between plus fit and sturdy fit school trousers?

Nothing. They are two names for the same cut, wider at the waist and seat with a shorter leg for that waist size. Different retailers use different words, which is genuinely confusing when you are trying to compare. Some also call it generous fit or comfort fit.

Are pull on school trousers smart enough for secondary school?

Yes. Our full elastic trousers are made in the same fabric with the same flat front and the same straight leg as the fastening versions, and the elastic sits under the waistband rather than on show. Most schools specify colour and general style rather than fastening type, but if the uniform policy is strict it is worth a quick check with the office.

My child is between two sizes. Which way should I go?

Go up on the waist and deal with the length separately, either by choosing a sturdy fit or by using the shortening option. Trousers that are slightly long can be worn. Trousers that do not fasten cannot.

Do you offer exchanges if the size is wrong?

We do not run exchanges, and there is a good reason for it. An exchange means waiting for the original pair to travel back to us before the replacement goes out, which in late August can cost you over a week. Instead, order the correct size straight away and return the first pair for a refund. Your child gets wearable trousers days earlier. Returns are processed within fourteen days of arriving with us.

How quickly will they arrive?

Most orders leave our warehouse within one to two working days, and delivery timings run from the point of dispatch. UK delivery starts at £3.50 and is free on orders over £75. Full detail is on our delivery and returns page.