Here is the measurement for Crochet hats

SKILL LEVEL

 
MATERIALS
  Medium (worsted) weight wool yarn
  Colors : Yellow, Blue, Black, White and Grey 
  Size 5.0mm crochet hook
  Pattern is for kids 3 to 5 years.
  Click for other age measurements.

ABBREVIATIONS AND SYMBOLS
  SS = Slip Stitch (.)
  SC = Single Crochet (+)
  BLO = Back Loop Only

INSTRUCTION
Rnd 1)
     With Color: Yellow
     Magic Loop + Chain 1 
     Ch 1 + 10 SC into the main ring + slip Stitch
Rnd 2)
    (Ch 1 + 2 SC)into the same stitch + 2 SC around + slip stitch.
Rnd 3)
    (Ch 1 + 1 SC) into the same stitch + 2 SC in the next stitch + [1 SC + 2 SC]* around + slip stitch.
Rnd 4)
    (Ch 1 + 1 SC) into the same stitch + 1 SC in the next stitch + 2 SC in the next stitch + [ 1 SC + 1 SC + 2 SC]* around + slip stitch.
Rnd 5)
   (Ch 1 + 1 SC) into the same stitch + 1 SC in the next stitch + 1 SC in the next stitch + 2 SC in the next stitch [ 1 SC + 1 SC + 1 SC + 2 SC]* around + slip stitch.
Rnd 6 to 9)
    (Ch 1 + 1 SC) in the same stitch + [1 SC]* around + slip stitch.
Rnd 9 - 10)
Change Color : Black
    (Ch 1 + 1 SC) in the same stitch + [1 SC]* around + slip stitch.
Rnd 11 - 14)
Change Color : Yellow
    (Ch 1 + 1 SC) in the same stitch + [1 SC]* around + slip stitch.
Rnd 15 - 17)
Change Color : Blue
    (Ch 1 + 1 SC) in the same stitch + [1 SC]* around + slip stitch.

Eyes: Make 2 
Rnd 1)
With Color : Black
     Magic Loop + Chain 1 Ch 1 + 10 SC into the main ring + slip Stitch
Rnd 2) 
Change Color : White
   (Ch 1 + 2 SC)into the same stitch + 2 SC around + slip stitch. 
Rnd 3)  
    (Ch 1 + 1 SC) into the same stitch + 2 SC in the next stitch + [1 SC + 2 SC]* around + slip stitch.
Rnd 4) 
Change Color : Grey 
    (Ch 1 + 1 SC) into the same stitch + 1 SC in the next stitch + 2 SC in the next stitch + [ 1 SC + 1 SC + 2 SC]* around + slip stitch. 
Rnd 5)
    BLO - (Ch 1 + 1 SC) in the same stitch + [1 SC]* around + slip stitch.
Rnd 6)
   (Ch 1 + 1 SC) in the same stitch + [1 SC]* around + slip stitch.
Mouth:
Chain 10
Row 1) 1 SC in each chain

Sewing:
Insert some cotton for the eyes and stitch it in such a way that the sewing thread is not visible on the back side. Sew the mouth and insert some black yarn for hair if needed.

Flat Circle for the top:

Round 1 : Magic Loop and 11 DC in that loop  +Slip Stitch into the 3^rd chain
( Total 12 DC)

Round 2 :  Chain 3 + 1 DC in the same stitch + (2 DC) * around  + Slip Stitch into the 3^rd chain
( Total 24 DC )

Round 3 :  Chain 3 + 2 DC in the next stitch + (1 DC + 2 DC) * around + Slip Stitch into the 3^rd chain
( Total 36 DC )

Round 4 :  Chain 3 + 1 DC in the next stitch + 2 DC +
( 1 DC + 1DC + 2 DC)* around) + Slip Stitch into the 3^rd chain
( Total 48 DC )

Round 5 :  Chain 3 + 1 DC in the next stitch + 1 DC + 2 DC +
( 1 DC + 1DC + 1DC + 2 DC)* around + Slip Stitch into the 3^rd Chain.
( Total 60 DC)

Round 6 :  Chain 3 + 1 DC in the next stitch + 1 DC + 1 DC + 2 DC +
( 1 DC + 1DC + 1DC + 1 DC + 2 DC)* around + Slip Stitch into the 3^rd Chain.
(Total 72 DC)

Round 7 : Chain 3 + 1 DC in the next stitch + 1 DC + 1 DC + 1 DC +
2 DC +
(1 DC + 1DC + 1DC + 1 DC + 1DC + 2 DC)* around + Slip Stitch into the 3^rd Chain.
 (Total 84 stitches)

Hat Body

Round 1 :  Chain 3  +  Skip 2 Stitches  + ( 2 DC + CH 1 + 2 DC  – Shell) + (Skip 2 Stitches + 1 DC  + Skip 2 Stitches + Shell)* around  + Slip Stitch into the 3rd Chain.

Round 2 :  Ch 1 + Front Post Single Crochet ( FPST ) around the previous chain 3 + Ch 1 + Shell in the previous shell + (Front Post Double Crochet ( FPDT ) in the previous DC + Shell in the previous shell)* around  + Slip Stitch into the 3rd Chain.

Round 3 to Round 10 : Same as Round 2

Round 11 : To Flatten out
Ch 1 + Front Post Single Crochet ( FPST ) around the previous chain 3 + Ch 1 + [(1 HDC + 1 SC + SL ST + 1 SC + 1 HDC)  + FPDT in the previous DC]* around  + Slip Stitch into the 3rd Chain.