🎒 School Uniform
School Blazer Size Guide
School blazers are sized by chest in inches — measure around the fullest chest and allow room for layers.
Blazers (and jumpers) are sized by chest in inches — a '30 chest' blazer. Measure around the fullest part of the chest, under the arms, over a shirt, and allow a little room for a jumper underneath.
Sized by chest (inches)
Measure fullest chest; allow room for layers
School blazer chest sizes by age:
| Age | Chest (in) | Chest (cm) | Height |
|---|---|---|---|
| 3–4 years | 21–22" | 53–55 cm | 98–104 cm |
| 4–5 years | 22" | 55–57 cm | 104–110 cm |
| 5–6 years | 22–23" | 57–59 cm | 110–116 cm |
| 6–7 years | 23–24" | 59–61 cm | 116–122 cm |
| 7–8 years | 24–25" | 61–64 cm | 122–128 cm |
| 8–9 years | 25–26" | 64–67 cm | 128–134 cm |
| 9–10 years | 26–28" | 67–70 cm | 134–140 cm |
| 10–11 years | 28–29" | 70–73 cm | 140–146 cm |
| 11–12 years | 29–30" | 73–76 cm | 146–152 cm |
| 12–13 years | 30–31" | 76–80 cm | 152–158 cm |
| 13–14 years | 31–33" | 80–84 cm | 158–164 cm |
| 14–15 years | 33–35" | 84–88 cm | 164–170 cm |
| 15–16 years | 35–36" | 88–92 cm | 170–176 cm |
⚠️ Allow room for a jumper underneath, and size up for growth — a blazer should last the year.
Uniform size calculator → · All school uniform guides →
How are school blazers sized?
By chest measurement in inches. Measure around the fullest chest under the arms; that inch figure is the blazer size.
Should a school blazer be loose?
A little — enough for a jumper underneath and room to grow, without the shoulders dropping off.
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