About the Kids' Clothing Size
The Kids' Clothing Size Converter estimates a child's clothing size across US, UK and EU sizing systems from their age alone, since the three regions size children's clothes in fundamentally different ways. It is meant for shoppers ordering from an international retailer who only know a child's age and need a starting size to select.
How It Works
Enter the child's age in years. The calculator first estimates an average height for that age using a simple linear formula, then rounds that estimated height to the nearest even centimeter to produce an EU size, since European children's sizes are labeled directly by height, for example size 104 or 110. US and UK sizes are shown as the age itself in years, with a note that ages under 2 typically use toddler sizing (2T to 4T) instead.
Examples
5-year-old, default input
A 5-year-old has an estimated height of 105.5 cm, giving a US/UK size of 5 years and an EU (height-based) size of 106.
1-year-old toddler
A 1-year-old has an estimated height of 79.5 cm, giving an EU size of 80, while the US/UK figure is floored at 2, shown as '2 (or 2T-4T for toddlers)'.
Advantages
- Bridges age-based sizing (US/UK) and height-based sizing (EU) from a single input, without needing a tape measure on hand.
- Flags the toddler-specific US labeling (2T-4T) rather than just returning a plain number that wouldn't appear on a toddler size tag.
- Gives a numeric EU size in the even-number increments, like 92, 98 or 104, that European brands actually print on their labels.
Common Mistakes
- Treating the EU size as exact rather than an age-based estimate, when a directly measured height will always be more reliable for that system.
- Not accounting for a child who runs noticeably tall or short for their age, which this age-only estimate can't detect.
- Assuming US and UK children's sizing maps to age the same way at every age, when both systems commonly shift to letter-based sizing outside the core years this simple mapping covers.
Edge Cases to Watch For
- The height estimate is a straight-line approximation, 73 cm plus 6.5 cm per year of age, and doesn't model the real slowdown in growth rate that happens as children get older, so it becomes less precise outside the toddler and early school-age range.
- For any age under 2, the US/UK figure is floored at 2, so a 6-month-old and a 2-year-old both display as size 2 in that system even though the underlying estimated height differs substantially.
- Because it relies on age rather than a measured height, the EU size shown here is a starting point only. A child who is notably taller or shorter than average for their age will fit better in the size matching their actual measured height.
Common Use Cases
- Parents or gift-buyers ordering children's clothing from a European retailer that sizes by height.
- Shoppers comparing a US size tag against an EU size tag while browsing an international marketplace.
- Retailers or resellers converting a customer's stated child age into an approximate size for a size-guide or FAQ.