Hat Measurements for Crochet and Knit

Driving yourself crazy trying to crochet the correct size hat? Here is your answer – a complete list of head and hat measurements as you crochet and knit hats so you can get the perfect size.

Head and Hat Measurements for Crochet and Knitting

Basically, you take the head measurement and subtract it by one to one and a half inches to get the measurement for the finished hat, since the hat will stretch. Of course, that really depends on the stretch of your yarn, hook or needle size, and your gauge! I know, sorry it can’t be simpler. For instance, Sugar’n Cream yarn is 100% cotton and has very little stretch, but acrylic yarn (like Lion Brand’s Vanna’s Choice yarn) has a lot of stretch. So, plan accordingly! For me, that means I end up experimenting a lot and unraveling some work. However, I must say that I’ve made many a hat that wasn’t just the right size, most of them a little too big, and, with the exception of preemies and newborns, the hats looked great on each lucky head.

Now, if you have a math brain, Inner Child Crochet says you can take the head measurement, subtract 15%, and then divide by pi (3.14). Bet you thought you’d never have to use that again, did ya? Especially not for crafts! I did test this out on one of my hats – I folded the hat in half and measured the distance across (not perfectly accurate, but close enough for me). The distance is 9 inches, so multiply that by 2 to get the circumference – 18 inches. Take 15% of 18 (or multiply by .85), and you get 15.3, then divide by 3.14 and you get 4.87, which is about the diameter of the crown of my hat!

For the hat circumference, measure from the forehead all the way around. For the hat height, measure from the crown of the head to the base of the ear for winter hats, but for summer hats that have a brim and rest above the ears, only measure to the top of the ear. Take a look at Wooly Wormhead’s pictures for more help.



Head Circumference: 13 to 14 inches (33 to 36 cm)
Hat Circumference: 11.5 to 13 inches (29 to 33 cm)
Hat height (winter hat): 5.5 to 6 inches (13 to 15 cm)


Baby – 3 to 6 months

Head Circumference: 14 to 17 inches (36 to 43 cm)
Hat Circumference: 12.5 to 14 inches (32 to 36 cm)
Hat height (winter hat): 6.5 to 7 inches (15 to 18 cm)


Baby – 6 to 12 months

Head Circumference: 16 to 19 inches (41-48 cm)
Hat Circumference: 14.5 to 16 inches (37 to 41 cm)
Hat height (winter hat): 7.5 to 8 inches (19 to 46 cm)


Toddler – 12 months to 3 years

Head Circumference: 18 to 20 inches (46 to 48 cm)
Hat Circumference: 16.5 to 18 inches (42 to 46 cm)
Hat height (winter hat): 8 inches (20 cm)


Child – 3 to 10 years

Head Circumference: 19 to 20.5 inches (48 to 51 cm)
Hat Circumference: 17.5 to 19 inches (44 to 48 cm)
Hat height (winter hat): 8.5 inches (22 cm)


Pre-Teens and Teens

Head Circumference: 20.5 to 22 inches (53 to 56 cm)
Hat Circumference: 19 to 20.5 inches (48 to 52 cm)
Hat Height (winter hat): 9 to 10 inches (25 cm)


Adult Woman 

Head Circumference: 21.5 to 22.5 inches
Hat Circumference: 20 to 21.5 inches (48 to 57 cm)
Hat height (winter hat): 11 inches (28 cm)


Adult Man 

Head Circumference: 23 to 24 inches (58 to 61 cm)
Hat Circumference: 21.5 to 23 inches (55 to 58 cm)
Hat height (winter hat): 11 to 11.5 inches (28 to 29 cm)

Merry Crocheting!

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About Sara McFall

Sara is the owner and founder of My Merry Messy Life, which started in 2011 as a way to chronicle her journey to a natural, chemical-free lifestyle and to share her passions of mothering, real food, homeschooling and crochet. She is a mama to three precious and energetic little boys and wife to a university professor who loves to sing, dance ballet and ballroom, and live simply and naturally.


  1. Thank you! These measurements are SO helpful. I want my gift to be a surprise to the child and the mother. No asking for measurements.

  2. Thank you soo much! But what I struggle with still is figuring out how many stitches and increases I need in order to obtain the desired width of the beanies. Im still learning and havent got the hang of all this measuring yet! If you know of any web sight that would have something like this it would be greatly appreciated. Thank you 🙂

  3. i am making baby hats for an orphanage and need to know how to determine what size hook i need for different age groups, i mostly use simply soft, or baby yarn. could you please answer to my email?
    thanks, patricia

    • Hi there Patricia! Well, in general, you would use a smaller hook for smaller heads and larger for larger. So, a G hook would be good for newborns and babies, an H for older babies, an I for toddlers…and so on. Does that help?

  4. Thank you for this info!!!! So very useful! I will make good use of it!

  5. I love having a chart! I’m having trouble though. I just made a hat for a 3 year old (16 inch head) and although I measured the diameter of the increase portion and it was accurate, the hat came out 17 inches in circumference! And when I make them as long as it says, for the hat height, I find they come down too far on the child’s face. Any suggestions??

  6. Silly question but here goes….
    making a sun hat what is the difference between winter height and summer height?

    Loving this pattern and the useful information also provide thanks very much.

  7. Abby Doolin says:

    When should you start decreasing, and how many decreases per round are normal?

  8. Hi Sara,
    Thank you for your excellent explaination.
    i want to ask you if summer hats are the same measurments on length like the winter ones .
    im talking about the edges on the round…
    thank you in advance

  9. Cathy faust says:

    Where can I find the pattern for the hats shown in the picture at the top of this page ??

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