| Size | To fit chest circumference |
| Age 1–2 | 48–51 cm (19–20 in) |
| Age 2–4 | 53–58 cm (21–23 in) |
| Age 4–6 | 58–63 cm (23–25 in) |
| Age 6–8 | 63–68 cm (25–27 in) |
| Age 8–10 | 68–71 cm (27–28 in) |
| Age 10–12 | 71–76 cm (28–30 in) |
| 1 | 78–81 cm (30–32 in) |
| 2 | 86–91 cm (34–36 in) |
| 3 | 97–102 cm (38–40 in) |
| 4 | 107–112 cm (42–44 in) |
| 5 | 117–122 cm (46–48 in) |
| 6 | 127–132 cm (50–52 in) |
| 7 | 137–142 cm (54–56 in) |
| 8 | 147–152 cm (58–60 in) |
| 9 | 157–162 cm (62–64 in) |