This crochet hat size chart includes all sizes by age from preemie baby to adult large. It includes three hat lengths to help you adjust crochet hat sizes from caps to beanies and slouchy hats. Also included in this chart are the head circumference, the hat circumference, and crown diameter to help you crochet hats that are worked from top-down and vice versa.

It is always best to take exact measurements of the person you are making hats for, but when that’s not possible, this chart can come in handy.

Generally speaking, hats are worked about 1-3 inches smaller than the actual head circumference. The amount of stretch you need will depend on the hat size, and the yarn and the stitch pattern that you are working with.

Bigger hats generally need more stretch than smaller hats, which means a baby hat might only need about 1 inch of stretch, whereas a large hat using the same yarn and stitch pattern might require anywhere from 2-3 inches of stretch.

In terms of yarn, not all yarns have the same amount of stretch even though they are made from the same material. For example, Vanna’s Choice and Red Heart Super Saver are both acrylic yarns, but Vanna’s Choice has a lot more stretch. With that said, acrylic yarn has more stretch than cotton. Thus, if working with a 100% cotton yarn, you might need to make your hat circumference the same as the head circumference.

Another thing to consider is the length of your hats. If making cancer caps and other slouchy hats, or if you want to fold the brim over you might want to add an additional 1-3 inches to the final length given here.

To get started, you will need to take measurements of your head using a flexible measuring tape. (If you don’t have one, you can use a string of yarn and measure that up against a ruler.) Place the measuring tape (or string) in the middle of the forehead and guiding it just above the ears measure around the head.

It’s very straightforward if you’re crocheting your hat from the bottom up. Simply make your circumference slightly less than the head circumference and continue in pattern until you’ve reached your desired height. But if you’re working from the crown down, you will need to know your diameter. To calculate the diameter, take your hat circumference and divide it by 3.14.

Below is the hat size chart by age, which includes one size per age including preemie, baby, toddler, child, teen, and adult small, medium and large. Please note that everyone’s head size is different, and thus you may need to add or minus anywhere from a half-inch to several inches to your measurements.

Now on to crocheting! Check out the main category of crochet hats, or check out a few of my personal favorites that will look great in all sizes: Single Crochet Beanie, ESC Striped Hat, and the Two Together Beanie.