School Uniform Sizing: Size Runs, Fitting Kits and Buffer Stock

Build the run from enrolment, not from a template

Supplier size templates are averages across every school they serve, which means they are wrong for yours in a specific and predictable way. An international school with a large early-years intake has a different curve from a secondary with a sixth form, and both differ from the template.

Your enrolment data by year group is the better starting point, converted to sizes using last year's actual issue records if you have them. If you do not have them, this year is when to start keeping them: what size each student took, by year group, in a spreadsheet. It is the single most valuable procurement document a school can build, and it takes one person one afternoon.

Why the ends of the curve get missed

Every school over-orders the middle and under-orders the extremes. It happens because the middle is where most students are, so it feels like the safe place to concentrate, and because the extremes are where suppliers quietly stop grading.

The cost is asymmetric, and that is the part worth understanding. An unsold middle-size polo is a small loss you will probably clear next year. An unavailable extreme size is a student without uniform, a parent conversation, and an emergency order at courier rates. Plan the extremes generously and the middle tightly, not the reverse.

Ask any supplier where their grading stops before you order. A curve that ends short at either end is the most common complaint we hear about a school's previous supplier, and it is invisible in a quotation.

Fitting kits

A fitting kit is one garment in every size, sent ahead of the bulk order, that families try on at an enrolment or open day. It costs a set of samples and one afternoon of somebody's time.

What it buys is a size distribution taken from your actual students rather than estimated from a chart, which is the difference between ordering roughly right and ordering right. It also removes almost all size-exchange traffic, because a parent who has seen the garment on their child does not order the wrong one — and exchanges are where the administrative cost of a uniform programme actually sits.

Schools running a fitting kit for the first time are usually surprised by how far their real distribution sits from the chart. That surprise is the whole return on it.

The size grading we run, including the ends of the curve most suppliers skip, is on our school uniform page.

Buffer stock, sized properly

Mid-year joiners, growth spurts and losses are certain; the only question is whether you have planned for them. As a starting point, hold around 10% above forecast on the highest-volume garments, weighted toward the sizes your data says move fastest, plus a small allocation at each extreme.

Look at last year: how many students joined after the start of term, and what did you do about it? A school that ran three emergency courier orders last year is paying far more than the buffer would have cost. A school that never ran one is probably over-buffering.

Buffer on the polo and PE top before anything else. Those are worn daily, replaced most often, and the ones a joining student needs immediately.

Keeping fit identical across years

A size 9-10 polo must mean the same thing next year as this year, or you will get complaints that read as quality complaints but are actually consistency complaints. That is a supplier commitment, and it is worth asking about explicitly.

What makes it work is that your approved sample and graded measurement chart stay on file and every reorder is produced against them rather than re-derived. When we quote a reorder, it is cut to the same pattern and inspected against the same measurements, which is why a reorder skips development entirely.

If a supplier cannot tell you how they hold grading across years, assume they do not, and expect a fit change at some point during your cohort's time at the school.