School Shorts and Trousers: A Fit and Size Guide

School shorts and trousers fail on fit far more often than they fail on quality. In our Johannesburg store, the returns are rarely about a broken seam. They are about a waistband that gapes at the back, a hem that drags on the floor, or trousers that sit well at the waist and pinch across the thigh.

Roughly 12.6 million children aged 7 to 17 were in school in 2024, out of 12.9 million in that age group (Children Count), and almost all of them wear the same two or three items five days a week. Getting the size wrong is expensive. Uniform and stationery prices rose by around 8% year on year ahead of the 2026 school year (Saturday Star), and equipping one Grade 8 pupil at a public high school is estimated at a minimum of R5,000 before stationery (The Witness).

This guide covers the three measurements that decide a fit, the room to leave, why a short and a trouser behave differently, and the fixes for the common faults.

The Three Measurements to Take at Home

You need a soft tape measure, a pencil and a hard floor. Measure in the evening, over the vest your child wears to school, never over jeans.

• Waist. Find the crease above the hip bone where the body bends sideways. Run the tape around that line, level front and back, one finger under it. Snug enough to stay up on its own, loose enough to turn.
• Rise. From the crotch seam up to the top of the waistband, taken on the body with the child standing straight.
• Inseam. From the crotch seam down the inside of the leg to where the hem should sit. The knee for shorts. The top of the school shoe for trousers, with shoes on.

Three numbers, taken once in October, save a return in January.

Write the three numbers on a card for the school bag. The table was measured flat on stock in our store: find the waist first, then check the inseam. Between two rows, take the smaller short and the larger trouser.

Size label	Waist (cm)	Short inseam (cm)	Trouser inseam (cm)
3-4 years	50 to 53	17	38
4-5 years	52 to 55	19	41
7-8 years	56 to 59	23	50
10-11 years	61 to 65	27	58
13-14 years	67 to 71	30	65
15-16 years	72 to 77	32	70
16-17 years	74 to 79	33	72
18 years	77 to 82	34	74

A label is an age band, not a waist size. Two children in one Grade 4 class can be several sizes apart at the waist and the same height. Trust the tape.

How Much Growth Room to Leave

Every parent has bought the size up in January so the item lasts to December. It rarely works. A child in trousers two sizes too big walks on the hem and wears through the fold.

Where the room goes	How much	What it buys	Check before you cut the tag
Trouser waist	2 cm	About a year on a primary school child	Waistband stays up without a belt
Short waist, elastic	2 to 3 cm	One growth spurt	Elastic does not twist when sitting
Trouser hem	4 to 5 cm	One let-down, Grade 4 to Grade 7 growth	Hem clears the shoe by 1 to 2 cm
Short hem	2 to 3 cm	One small let-down	Hem still reaches the knee
Seat	1 cm	Room to sit without pulling	No pull lines across the seat

Two centimetres at the waist is one waistband width: invisible, and it buys a year. Four to five centimetres at the trouser hem buys one let-down. Shorts need less, because a hem let down twice looks wrong.

Two centimetres of room is invisible. Two sizes of room is obvious.

Test it before you cut the tag. Put it on, fasten it, and ask the child to sit on the floor and stand up. If the waistband stays up without a belt, the room is right. If it needs the belt, the item is too big, not roomy. Shoes shift the sum too: children's feet can grow half a size every two months while they are small (Stride Rite kids fit guide), so a hem planned around January shoes sits high by June.

Why One Size Fits Two Ways in a Short and a Trouser

This catches out most parents in the shop. A Grey School Short from R54.99 and a pair of Grey School Pants from R151.99 in the same age band are not the same garment with a shorter leg. They are cut from different blocks.

A short is built to be sat in on the floor and washed twice a week: shorter rise, wider leg, elastic waist. A trouser is built for a tucked shirt and a belt: longer rise, straighter leg, fixed waistband, and more fabric through the seat so the back seam does not pull.

What changes	Grey school short	Grey school trouser
Front rise	Shorter, sits on the hip	Longer, sits at the natural waist
Waistband	Elastic or part elastic, no belt needed	Fixed, with belt loops and a button
Leg	Wider through the thigh and hem	Straighter, with a slight taper
Seat	Little allowance, cut for movement	Extra allowance, cut for sitting
Hem	At the knee or just above it	Meets the top of the shoe
What to check	That the elastic does not twist	That the seat does not pull when seated

At the same label the trouser feels tighter at the waist and looser at the thigh. If a child measures 60 cm and the short fits with room, the trouser may fasten but will bite by the afternoon. Size up and take the waist in.

The label on the tag is a starting point. It is not a promise.

That also explains why a hand-me-down that fitted an older sibling can be tight on a younger child with the same waist reading. When a pair stops fitting, pass it on: polycotton blends can linger for decades in landfill (Rethread).

Elastic, Fixed or Part Elastic: Choosing the Waistband

Three waistband types cover almost every short and trouser sold in South Africa.

• Full elastic. A channel of elastic all the way round, no zip. It suits Grade R to Grade 4, when children dress themselves.
• Part elastic. Elastic at the back, flat front with a button and zip. The compromise that suits most primary school children, and any child with a slim waist.
• Fixed waist. Flat all the way round with a zip, button and belt loops. Standard from about Grade 4 up, and required by any code that specifies a belt.

Elastic is not automatically comfortable. A wide band rolls over when the child sits, and worn elastic loses its snap after a year of hot washes. A fixed waist holds its line but has no forgiveness: 3 cm out and the child feels it all day. A shirt that stays tucked keeps the waistband flat, so the Short Sleeve Shirt from R93.99 is part of the fit.

Five checks in the shop tell you most of what matters.

• Stretch the waistband to twice its width and let go. It should snap back flat.
• Look at the stitching along the top of the waistband. One row is a cheap finish. Two rows hold.
• Check the buttonhole. A bound one lasts. A slit cut into the fabric frays within a term.
• Run a thumb along the inside of the side seam. Loose overlocking opens at the knee or the seat.
• Turn the item inside out and look at the crotch seam. It should be double stitched, with no puckering.

A waistband that will not stay up is a bad waistband, not a growing child.

Check the school code before you buy. The National Consumer Commission reminds parents that exclusive supply should be limited to items that genuinely need it, such as a badge (NCC consumer alert). The Competition Commission resolved 465 uniform complaints between 2020 and 2025 (Daily Maverick). A plain grey item that matches the code is usually fine.

How Long Should the Hem Sit?

For shorts, the hem belongs at the knee or no more than 2 cm above it. Below the knee it catches on chairs and gets stood on in a queue. Above mid thigh, most codes send the child home to change.

A hem that touches the floor will not survive a term of tar and stairs.

For trousers, the hem should meet the top of the shoe with one soft break, the crease that forms where the fabric touches the shoe (Primer on alterations). No pool of fabric on the instep, and no daylight between hem and shoe. A thick sock lifts the foot inside the shoe, so put on the Grey School Socks at R24.99 before you mark a hem.

• Sit test: the child sits, crosses their legs, then stands. Nothing should pull at the knee or the seat.
• Stair test: walk up a flight. The hem should not brush the step behind.
• Shoe test: stand still in school shoes. The hem should touch the shoe, not float above it.

The South African school year decides which you buy first. In 2026 Term 1 runs from 14 January to 27 March and Term 4 from 6 October to 11 December (school calendar), so close to half the year is hot.

Term	2026 dates	What most families wear	Why
Term 1	14 January to 27 March	Shorts	The hottest weeks of the Gauteng year
Term 2	8 April to 26 June	Shorts, trousers from late May	Mornings cool sharply from mid May
Term 3	21 July to 23 September	Trousers	Coldest term, frost on early Joburg mornings
Term 4	6 October to 11 December	Shorts, trousers for formal days	Heat returns, and prize giving needs a trouser

On the Highveld the gap between 7 am and 2 pm is large, so shorts plus a jersey cover most of the year. On the KwaZulu Natal coast, humidity matters more than cold: a polycotton short dries overnight, a heavy trouser does not.

Tracksuit Pants as the Third Option

Most families end up with two pairs of trousers and one tracksuit pant. The Blue School Tracksuit Pants from R249.99 is the usual third piece: elastic waist, straight leg, tough fabric. They earn their place on sport days and cold mornings, but do not replace trousers for assembly or an exam.

• Size by height and ankle, not waist. The elastic covers a range of waists, but leg length cannot be adjusted.
• Check the ankle cuff. Too tight and it rides up the calf. Too loose and it drags.
• Look at the knee. That is where the wear goes, so a double layer knee is worth the extra.
• Buy two if sport runs three times a week. One on the line and one on the child beats a wash at nine at night.

The pair that gets worn is the pair that fits at the ankle and the waist.

A polycotton blend holds its shape and resists shrinking better than pure cotton (Dressfresh care guide, Kentaur wash guide). Wash inside out in cool water, skip the tumble drier, dry flat. Elastic fails first, and heat is what kills it.

What Do You Do When the Fit Is Wrong?

Almost every fit fault falls into five patterns.

What you see	Most likely cause	The fix
Gap at the back of the waist	Waistband 2 cm or more too big, or a straight waistband on a slim child	Take in the back seam by up to 2 cm, or move to part elastic
Hem drags on the ground	Bought a size up for next year	Turn up 4 cm on a temporary stitch, let it down in a year
Tight across the thigh	Short cut narrow, or the trouser sized on the waist alone	Size up and take in the waist. Never take in the thigh
Waistband rolls when sitting	Elastic too wide for a short torso	Choose narrower elastic or a part elastic waist
Seat pulls when sitting	Rise is too short	Size up, or choose the style with the longer rise

Two fixes need a sewing machine and three do not. A hem take-up and a back seam take-in are the cheapest alterations at any tailoring shop. Before you count on a let-down, check inside the hem: a good trouser has 4 to 5 cm turned up, a cheap one is overlocked.

• Fixes that work: a safety pin folded flat at the back waist, iron-on tape, a belt on a fixed waist.
• Fixes that make it worse: cutting the hem shorter, taking in the thigh, washing hot to shrink it.
• Fixes worth paying for: a proper hem, a back seam take-in, a new zip.

Most uniform failures are two centimetres of sewing away from a fix.

Each price is the lowest in that size range.

Item	Price	Sizes	What it solves
Grey School Short	R54.99	4-5 to 18 years	Hot terms, PE and floor sitting
Grey School Pants	R151.99	3-4 to 15-16 years	Winter, formal days and exams
Blue School Tracksuit Pants	R249.99	20 to 44	Sport, cold mornings and camps
Grey School Socks	R24.99	S, M, L	Hem clearance and shoe fit
Short Sleeve Shirt	R93.99	3-4 to 16 years	Stays tucked, so the waistband sits flat

New to this? Our school uniform size guide covers the tape method item by item, and the grey school uniform buying guide lists everything for a Johannesburg school. Shoes move the hem line, so read the school shoe guide first, then browse the full school uniform range and school socks.

Frequently Asked Questions

The five questions South African parents ask us most in October and November.

What size school shorts should I buy for a Grade 1 child?

Start from the waist, not the grade. A Grade 1 child usually measures between 52 and 60 cm at the waist, which puts most of them in a 4-5 or 7-8 year label. If the waist sits at the top of a band and the child is tall, take the larger short: the hem has 2 to 3 cm to let down.

Can a trouser hem be let down later?

Sometimes. A well made trouser is hemmed with 4 to 5 cm folded inside, enough for one let-down of about 4 cm. Turn it inside out and look at the hem allowance before you promise the child another year: a deep fold means yes, an overlocked edge with a few millimetres means no.

Should school shorts sit above or below the knee?

At the knee, or no more than 2 cm above it. Below the knee the fabric catches on chairs and gets stepped on in queues. Above mid thigh, most codes send the child home to change. A few schools also specify a length in centimetres, so read the code.

Is it better to buy school trousers one size bigger?

One size, no more. A size up gives roughly 2 to 3 cm at the waist and 4 to 5 cm at the hem, about a year of growth on a primary school child. Two sizes up gives a hem the child walks on and a crotch that hangs low.

How do I stop the waist gaping at the back?

Gaping at the back is almost always a waistband that is too big, not a body shape problem. Pinch the excess at the centre back while the child stands straight. More than 2 cm, and a tailor should take in the back seam, or you switch to a part elastic waist.

If you would rather not do the sums in the aisle, bring the three numbers to us. We stock the grey range in Johannesburg, deliver nationally, and will tell you plainly when a size up is a waste of money.