Choosing LEGO for a child: how to read the age rating
What the number on the box tells you, where the safety advice for young children starts and what to look for when buying a gift.
Published on 18 October 2026
What the age rating tells you
Every LEGO box shows an age, such as 4+, 6+ or 9+. It helps you judge how hard a set is. The number of pieces alone says little about that, because the level of detail and the size of the set matter too. The label is a guideline. Some children build sets above their recommended age without trouble.
Very young children
LEGO Duplo is made for children from about one and a half to five. Its bricks are twice the size of standard LEGO bricks in every direction, which makes them easier to handle and harder to swallow. Regular sets with small pieces are not suitable for children under three, even under supervision. Some ranges with standard bricks start at 4 years. The box always gives the exact recommendation.
Tips for a gift
- Pick a theme the child already knows, such as a film, a vehicle or an animal.
- Go for a slightly smaller set the child can finish alone over a large set that stays in the box.
- Sets marked 18+ on the box are aimed at adult fans.
- Check the picture and the number of pieces in the shop, so you know what you are bringing home.
Then compare the price
Once you have chosen a set, compare the shops. The same set can cost a different price from shop to shop. On buildthatset you see what the shops charge, side by side.