Tu is Sainsbury's own kids' clothing label — and for most UK families it's the brand they reach for at back-to-school time. It's in every Sainsbury's, the prices are competitive, and the quality holds up through a full school year. Tu is also one of the 38+ brands tracked in Outgrow's cross-brand sizing research.
You've probably read — or heard from another parent — that Tu runs big. The data says otherwise. When we compare Tu's actual garment measurements against other brands at the same child height, Tu sits squarely within normal range. And when you put Tu's height brackets directly alongside Next and H&M, they align almost perfectly. A child in Tu 6-7 Years is in Next 6-7 Years too.
What's actually happening when Tu feels big is that parents are usually switching from a brand with a slightly narrower cut in the body — not a different size. The age label is fine. The real things worth knowing about Tu sizing are different, and this guide covers them.
Find your child's Tu size
Enter your child's measurements and we'll show the right size — plus how long it will last.
Size recommendations are based on official brand size charts and are provided as a guide only. Fit may vary by item, style, and individual child. Outgrow is not responsible for sizing decisions made based on these recommendations.
Does Tu Run Big? What the Size Chart Actually Shows
Mumsnet threads on Tu sizing go back years and the consensus is consistent: Tu runs generous, size down, my 6-year-old swims in the 6-7 Years. It's one of the most repeated pieces of sizing advice in UK parenting communities.
We measured Tu garment measurements against 30+ other brands at the same child height, and Tu sits squarely within normal range. We also compared Tu's height brackets directly to Next and H&M, and they align almost exactly across every age range. A child who is 120cm tall will land in Tu 6-7 Years, Next 6-7 Years, and the H&M equivalent. The label is consistent.
Where the feeling of extra room comes from is Tu's cut — slightly roomier through the torso than some competitors. That's a styling choice, not a sizing error. If your child is in the right height band, the Tu label is correct.
Tu vs Next vs H&M: How the Labels Compare at the Same Height
The most useful comparison for UK parents. Tu and Next are interchangeable in practice. H&M uses height numbers as labels rather than age ranges, which looks different but covers the same children at most heights.
| Child height | Tu label | Next label | H&M label |
|---|---|---|---|
| 100cm | 3-4 Years | 3-4 Years | 104 |
| 110cm | 5-6 Years | 4-5 Years | 110 |
| 115cm | 5-6 Years | 5-6 Years | 116 |
| 120cm | 6-7 Years | 6-7 Years | 122 |
| 128cm | 7-8 Years | 7-8 Years | 128 |
| 140cm | 9-10 Years | 9-10 Years | 140 |
The one exception: at exactly 110cm, Tu places children in 5-6 Years while Next places them in 4-5 Years — the only meaningful bracket difference across the range.
Tu School Uniform: The Three Fits Most Parents Don't Know About
This is Tu's most underused feature. School trousers come in Slim, Standard, and Generous fits at the same price. Most parents just grab the age label off the rail without realising there are three different garments hanging there.
Slim
Narrower waist and leg. For children who find Standard gapes at the waist despite the length fitting. A real difference, not a minor taper.
Standard
The default Tu trouser fit. Suits most children. Start here and use the adjustable waistband if you need fine-tuning.
Generous
Extra room in the waist, seat, and thigh. For children who find Standard snug at the waist before the length is outgrown.
Tu Boys Tops Size Chart
Boys and girls share identical chest measurements through 7-8 Years. From 8-9 Years onward the charts diverge as boys' chests grow faster.
| Label | Height (cm) | Chest (cm) |
|---|---|---|
| 9-12 Months | 74-80 | 50 |
| 12-18 Months | 80-86 | 51 |
| 18-24 Months | 86-92 | 52.5 |
| 2-3 Years | 92-99 | 53 |
| 3-4 Years | 99-104 | 56 |
| 4-5 Years | 104-109 | 58 |
| 5-6 Years | 109-117 | 61 |
| 6-7 Years | 117-122 | 64 |
| 7-8 Years | 122-128 | 64 |
| 8-9 Years | 128-134 | 67.5 |
| 9-10 Years | 134-140 | 71 |
| 10-11 Years | 140-146 | 74.5 |
| 11-12 Years | 146-152 | 78 |
| 12-13 Years | 152-158 | 83.5 |
| 13-14 Years | 158-164 | 86 |
| 14-15 Years | 164-170 | 88.5 |
| 15-16 Years | 170-176 | 91.5 |
| 16-17 Years | 176-178 | 97 |
| 17-18 Years | 178-180 | 102 |
Tu Girls Tops Size Chart
| Label | Height (cm) | Chest (cm) |
|---|---|---|
| 9-12 Months | 74-80 | 50 |
| 12-18 Months | 80-86 | 51 |
| 18-24 Months | 86-92 | 52.5 |
| 2-3 Years | 92-99 | 53 |
| 3-4 Years | 99-104 | 56 |
| 4-5 Years | 104-109 | 58 |
| 5-6 Years | 109-117 | 61 |
| 6-7 Years | 117-122 | 64 |
| 7-8 Years | 122-128 | 64 |
| 8-9 Years | 128-134 | 67 |
| 9-10 Years | 134-140 | 71.5 |
| 10-11 Years | 140-146 | 74.5 |
| 11-12 Years | 146-152 | 78 |
| 12-13 Years | 152-158 | 80 |
| 13-14 Years | 158-164 | 82.5 |
| 14-15 Years | 164-166 | 84.5 |
| 15-16 Years | 166-170 | 87 |
| 16-17 Years | 170-176 | 88.5 |
| 17-18 Years | 176-180 | 90 |
Tu Boys Bottoms Size Chart
| Label | Height (cm) | Waist (cm) | Hip (cm) | Inseam (cm) |
|---|---|---|---|---|
| 9-12 Months | 74-80 | 48.5 | 50 | 32 |
| 12-18 Months | 80-86 | 50 | 51.5 | 35 |
| 18-24 Months | 86-92 | 50.5 | 53 | 38.5 |
| 2-3 Years | 92-99 | 53 | 56 | 43 |
| 3-4 Years | 99-104 | 53 | 61 | 46 |
| 4-5 Years | 104-109 | 56 | 61 | 51 |
| 5-6 Years | 109-117 | 56 | 64 | 51 |
| 6-7 Years | 117-122 | 56 | 66 | 56 |
| 7-8 Years | 122-128 | 59 | 68 | 59 |
| 8-9 Years | 128-134 | 61 | 71 | 62.5 |
| 9-10 Years | 134-140 | 63.5 | 74 | 65 |
| 10-11 Years | 140-146 | 65 | 77.5 | 68 |
| 11-12 Years | 146-152 | 68 | 81 | 70.5 |
| 12-13 Years | 152-158 | 70 | 85 | 73 |
| 13-14 Years | 158-164 | 73 | 89 | 76 |
| 14-15 Years | 164-170 | 74.5 | 91.5 | 79 |
| 15-16 Years | 170-176 | 76 | 94 | 82 |
| 16-17 Years | 176-178 | 82 | - | - |
| 17-18 Years | 178-180 | 88 | - | - |
Hip and inseam not published by Tu for 16+ boys.
Tu Girls Bottoms Size Chart
| Label | Height (cm) | Waist (cm) | Hip (cm) | Inseam (cm) |
|---|---|---|---|---|
| 9-12 Months | 74-80 | 48.5 | 50 | 32 |
| 12-18 Months | 80-86 | 50 | 51.5 | 35 |
| 18-24 Months | 86-92 | 50.5 | 53 | 38.5 |
| 2-3 Years | 92-99 | 53 | 56 | 43 |
| 3-4 Years | 99-104 | 53 | 61 | 46 |
| 4-5 Years | 104-109 | 56 | 61 | 51 |
| 5-6 Years | 109-117 | 56 | 64 | 51 |
| 6-7 Years | 117-122 | 56 | 66 | 56 |
| 7-8 Years | 122-128 | 58 | 70 | 60 |
| 8-9 Years | 128-134 | 59.5 | 73.5 | 63 |
| 9-10 Years | 134-140 | 61.5 | 77 | 66 |
| 10-11 Years | 140-146 | 63 | 80.5 | 68.5 |
| 11-12 Years | 146-152 | 65 | 84 | 71.5 |
| 12-13 Years | 152-158 | 66 | 86 | 74.5 |
| 13-14 Years | 158-164 | 67.5 | 88 | 77.5 |
| 14-15 Years | 164-166 | 68.5 | 90 | 78.5 |
| 15-16 Years | 166-170 | 69 | 92 | 78.5 |
| 16-17 Years | 170-176 | 70 | - | - |
| 17-18 Years | 176-180 | 71 | - | - |
Hip and inseam not published by Tu for 16+ girls.
Tu Kids Shoe Size Chart
Tu publishes foot length measurements alongside UK and EU sizes. Use the foot length column for the most accurate match — measure from heel to longest toe with your child standing.
| Label | EU | UK | Foot length (cm) |
|---|---|---|---|
| UK 0-3 months | 16 | 0-3 mths | 9.5 |
| UK 3-6 months | 17 | 3-6 mths | 10.3 |
| UK Inf 2 | 18 | 2 | 11.0 |
| UK Inf 3 | 19 | 3 | 11.8 |
| UK Inf 4 | 20/21 | 4 | 12.6 |
| UK Inf 5 | 22 | 5 | 13.3 |
| UK 6 | 23 | 6 | 14.1 |
| UK 7 | 24 | 7 | 14.9 |
| UK 8 | 25/26 | 8 | 15.6 |
| UK 9 | 27 | 9 | 16.4 |
| UK 10 | 28 | 10 | 17.1 |
| UK 11 | 29 | 11 | 17.9 |
| UK 12 | 30/31 | 12 | 18.9 |
| UK 13 | 32 | 13 | 19.7 |
| UK 1 Jnr | 33 | 1 | 20.5 |
| UK 2 Jnr | 34 | 2 | 21.5 |
| UK 3 Jnr | 36 | 3 | 22.2 |
| UK 4 Jnr | 37 | 4 | 23.0 |
| UK 5 Jnr | 38 | 5 | 23.7 |
| UK 6 Jnr | 39 | 6 | 24.5 |
Frequently Asked Questions
Does Tu (Sainsbury's) kids clothing run big?
Not according to the size chart data. Tu garment measurements sit within normal range at the same child height, and the height brackets match Next and H&M almost exactly. The widespread "Tu runs big" advice likely comes from parents comparing Tu to brands with a narrower cut through the body. Use your child's height to find the right size and don't size down.
How does Tu sizing compare to Next kids?
Tu and Next use almost identical height brackets across all age ranges. A child in Next 6-7 Years will fit Tu 6-7 Years. The one small exception is at exactly 110cm, where Tu places children in 5-6 Years while Next places them in 4-5 Years. If your child is right at that boundary, check their height against the label before buying.
How does Tu sizing compare to H&M kids?
H&M uses height numbers as labels (110, 116, 122) rather than age ranges, which looks confusing but covers the same children at most heights. A child at 120cm would be in Tu 6-7 Years and H&M 122 - comparable garments, just differently labelled.
Does Tu do slim fit school trousers?
Yes - Tu school trousers come in Slim, Standard, and Generous fits at the same price. The fit name is on the tag at the back of the waistband. Slim is meaningfully narrower in the waist and leg, making a real difference for lean children who find standard trousers gaping at the waist.
What does the Tu age label mean?
Tu age labels like 5-6 Years mean the garment is designed for a child currently aged between 5 and 6. Always cross-reference with the height range on the label, as children of the same age vary significantly in height. A tall 5-year-old and a short 6-year-old often wear the same Tu size.
How should I size Tu school uniform?
Match your child's height to the Tu height range on the label - more reliable than the age. For trousers, choose Slim, Standard, or Generous based on your child's build rather than sizing up or down in the age label. Most Tu uniform trousers also have adjustable waistbands that give around 2cm of adjustment without changing size.