Find a polo shirt your child has in their closet that fits exactly how they like for the course.

Lay as flat as possible on a table. Using a tape measure, measure the chest and length measurements as shown here.

Once you have those measurements, use the BOYS or GIRLS guide above and below to determine what size most closely matches the garment you measured.

Use a soft tape measure and measure the circumference of your child's head. If you don't have a soft tape measure, use a piece of string to measure the circumference. Then lay the string flat and measure it with a ruler.

Measure above the eyebrows and ears where the hat will sit.