First, use a tape measure, take a firm measurement around the rib cage, directly underneath the chest. Hold it very firm and tight, so it doesn't slip down child's back.
Tip: Many of our girls bra styles do not have cup sizes, so match your ribcage measurement with child's clothing size to determine the best bra size.
![](https://www.fruit.com/on/demandware.static/-/Sites-fruit_us-Library/default/dw585a0aac/images/templates/size-guides/300x620/sizechart-girls-bras.png)