Find your child's Primark 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.
Primark is one of Europe's most popular budget clothing destinations for families — and one of 38 brands in our complete kids' clothing size guide. The prices make it easy to keep up with fast-growing kids without breaking the bank. But because Primark is primarily an in-store brand with limited online shopping in most markets, getting the size right before you go is especially important. There's no easy returns process when you've bought three school uniforms in the wrong size.
This guide covers Primark's complete size charts for babies, toddlers and kids, how their school uniform sizing works, how Primark compares to similar budget brands, and practical tips for shopping Primark with growing children.
Does Primark Kids Run Small, Large, or True to Size?
Primark kids clothing runs slim and slightly short — very much in line with other European high street brands. The cut is lean rather than generous, and parents who are used to US brands like Carter's or Gap often find they need to size up when buying Primark for the first time.
Key things to know:
- Primark sizes by age range on the label, but the underlying measurement is height-based like most European brands
- The fit is consistently slim across the range — there's little variation between categories in terms of how generous the cut is
- School uniform items run slightly more generous than fashion items — designed to last a full school year and accommodate movement
- Primark has been actively updating its sizing model with real body shape data, so consistency has improved in recent years
- Baby items run true to size — more reliable than the toddler and kids ranges
General rule: if your child is between sizes or on the larger side for their age, size up. Primark's slim cut means a tighter fit than US-standard parents expect.
Primark Baby Size Chart (0–36 months)
| Primark Size | Age Guide | Height (cm) | Weight (kg) |
|---|---|---|---|
| 0–3M | 0–3 months | Up to 62 cm | Up to 6 kg |
| 3–6M | 3–6 months | 62–68 cm | 6–7.5 kg |
| 6–9M | 6–9 months | 68–74 cm | 7.5–9 kg |
| 9–12M | 9–12 months | 74–80 cm | 9–10.5 kg |
| 12–18M | 12–18 months | 80–86 cm | 10.5–12 kg |
| 18–24M | 18–24 months | 86–92 cm | 12–13.5 kg |
| 24–36M | 24–36 months | 92–98 cm | 13.5–15 kg |
Primark Kids Size Chart (1.5–15 years)
Primark's kids range uses age-based labels with an underlying height guide. The sizing runs consistently across boys and girls lines.
| Primark Size | Age Guide | Height (cm) |
|---|---|---|
| 1.5–2Y | 18–24 months | 86–92 cm |
| 2–3Y | 2–3 years | 92–98 cm |
| 3–4Y | 3–4 years | 98–104 cm |
| 4–5Y | 4–5 years | 104–110 cm |
| 5–6Y | 5–6 years | 110–116 cm |
| 6–7Y | 6–7 years | 116–122 cm |
| 7–8Y | 7–8 years | 122–128 cm |
| 8–9Y | 8–9 years | 128–134 cm |
| 9–10Y | 9–10 years | 134–140 cm |
| 10–11Y | 10–11 years | 140–146 cm |
| 11–12Y | 11–12 years | 146–152 cm |
| 12–13Y | 12–13 years | 152–158 cm |
| 13–14Y | 13–14 years | 158–164 cm |
| 14–15Y | 14–15 years | 164–170 cm |
Primark School Uniform Size Guide
School uniform is one of Primark's most popular product categories — the price point makes it genuinely competitive, especially for items that will get heavy daily wear. But sizing school uniform correctly requires a slightly different approach.
Primark school uniform runs one size more generous than their fashion range. This is intentional — school uniform is designed to last a full academic year (September through July) with room to grow, whereas fashion items are sized for current fit.
Practical school uniform sizing strategy:
Measure in August, buy for September
Measure your child's height at the end of summer and use that as your guide. Don't size up based on predicted growth — Primark's uniform items already have growth room built in.
Shirts and polo shirts
Run slightly long in the body and generous in the chest. If your child is slim, stick to age. If they're stocky or broad-shouldered, size up.
Trousers and skirts
Primark trousers have adjustable waistbands on most styles up to age 11–12. Use the height as the primary guide and rely on the adjustable waist to get the fit right.
Blazers and sweatshirts
Run the most generously in the school uniform range — many parents find sizing down is better here to avoid an overly baggy look in September, at the cost of it being short by June.
The honest trade-off: Size for September and the item fits perfectly all year but may be tight by June–July. Size for the whole year and it looks baggy in September but fits well in spring. At Primark's price point, many parents buy two sets — one sized for current fit, one sized for growth — and rotate through the year.
Primark Kids Shoe Size Chart
| EU Size | UK Size | US Size | Foot Length (cm) |
|---|---|---|---|
| 19/20 | 3/4 | 4/4.5 | 11.5–12.5 cm |
| 21/22 | 5/6 | 5.5/6.5 | 13–14 cm |
| 23/24 | 6/7 | 7/7.5 | 14.5–15.5 cm |
| 25/26 | 8/9 | 8.5/9.5 | 16–16.5 cm |
| 27/28 | 9/10 | 10/10.5 | 17–17.5 cm |
| 29/30 | 11/12 | 11.5/12 | 18–19 cm |
| 31/32 | 12/13 | 12.5/1 | 19.5–20.5 cm |
| 33/34 | 1/2 | 2/2.5 | 21–21.5 cm |
| 35/36 | 3/4 | 3.5/4 | 22–23 cm |
| 37/38 | 4/5 | 5/5.5 | 23.5–24.5 cm |
How Primark Compares to Other Budget Kids Brands
Primark sits in a specific part of the market — genuinely low price point, European cut, strong on basics and licensed character clothing. The most relevant comparisons are with other budget and mid-market brands:
| Brand | vs. Primark |
|---|---|
| H&M Kids | Very similar sizing — both slim European cut. Usually interchangeable within the same age size. |
| George at Asda | Slightly more generous than Primark, particularly in the waist. Better for stockier builds. |
| F&F at Tesco | Similar to Primark — slightly longer in the body on tops. |
| Next Kids | Runs true to age and more generously than Primark. If your child fits Next 4–5Y, they'll likely need Primark 5–6Y. |
| Matalan | Similar to Primark in sizing, slightly wider cut. |
| Zara Kids | Very similar slim cut to Primark. Both run small vs US sizing. |
| Gap Kids | Runs much larger. A child in Primark 4–5Y will likely fit Gap 3–4Y. |
| Carter's | US sizing, runs generously. A child in Primark 3–4Y typically needs Carter's 2T–3T. |
Smart Shopping Tips for Primark with Growing Kids
Because Primark is predominantly in-store and prices are low, it invites a different shopping strategy than premium brands.
Buy less, more often.
The low price point makes it tempting to stock up — but children grow fast and Primark's slim cut means items can become too short before they're worn out. Buying 3–4 items at the right size now beats buying 8 items that are outgrown before they're used.
Use height as your guide, not age.
Primark's age labels are an average guide. If your child is taller than average for their age, trust the height column in the chart above and skip up a size.
Check the school uniform section year-round.
Primark keeps school uniform in stock most of the year, not just September. Sizes tend to be better in January–February when the September rush is over.
Basics are the best value.
Primark's licensed character items (Disney, Marvel etc.) are popular, but the plain basics — plain t-shirts, leggings, joggers — offer the best value per wear and are available consistently across all sizes.
How Long Will Primark Kids Clothes Last?
Primark's slim cut means items can feel outgrown in length before they wear out — a common parent complaint. Longevity is similar to other European brands but slightly shorter than generous US brands like Carter's.
| Primark Size | Average Wear Time |
|---|---|
| 0–3M | 6–10 weeks |
| 3–6M | 2–3 months |
| 6–9M | 2–3 months |
| 9–12M | 3–4 months |
| 12–18M | 3–5 months |
| 18–24M | 4–6 months |
| 2–3Y | 5–8 months |
| 3–5Y | 6–9 months |
| 5–8Y | 8–11 months |
| 8–11Y | 10–13 months |
| 11–15Y | 12–16 months |
School uniform items typically last one full school year (9–10 months of regular wear) if bought correctly sized.
Want to know exactly how long a specific Primark item will fit your child? The Outgrow app tracks your child's wardrobe across Primark and 35+ other brands and predicts how many months of wear you'll get from each item — so you can time your Primark runs perfectly rather than buying too early or finding things outgrown before they're worn.
Frequently Asked Questions
Does Primark kids run small?
Yes — Primark kids clothing runs slim and slightly short, consistent with other European high street brands. If your child is between sizes or broader in build, size up. Height is a more reliable guide than age.
Is Primark sizing the same as H&M?
Very similar. Both are European high street brands with a slim cut sized by height. Most children will find the same age size works in both — though it's always worth checking height against the chart since individual items can vary.
How does Primark school uniform sizing work?
Primark school uniform runs slightly more generously than their fashion range, with built-in growth room. Most items have adjustable waistbands up to age 11–12. Buy for September based on current measured height — don't size up significantly for growth as the items already account for this.
Does Primark sell kids' clothing online?
Primark has limited online availability in some markets. In the UK and most of Europe, Primark is primarily an in-store experience, which makes getting the size right beforehand particularly important. Check primark.com for current online availability in your country.
How do Primark sizes compare to Next?
Next runs true to age and more generously than Primark. If your child fits Next 4–5Y comfortably, they'll likely need Primark 5–6Y to get the same fit. Next is generally considered more reliably sized for UK children.
Are Primark shoes good for kids?
Primark shoes are suitable for casual and occasional wear but are not designed for all-day support for growing feet. For school shoes or primary footwear, a fitted children's shoe brand is recommended. Primark shoes work well as a second pair for weekends or holidays.
The Bottom Line on Primark Kids Sizing
Primark offers excellent value for growing kids — the trick is knowing that the slim European cut means sizing up from US norms, and that height beats age as a guide every time. For school uniform in particular, the price point is genuinely competitive if you get the sizing right from the start.
If you want to track exactly when your child will outgrow their Primark items — and time your next shopping trip perfectly — Outgrow covers Primark alongside 35+ other brands in one place.