What is the “average” measurements for a beanie (adult) - width/circumference, and length. When I make beanies they either look too big or too small. I know one size won’t necessarily fit everyone, but in general.
Patterns often give the circumference but not the length.
Beanie measurements
A traditional beanie runs about six inches from the cast on edge to the top. This is a very short beanie, though, and only reaches to the top of the ears. You have to look at the pattern pictures to see where this will hit in relation to the ear. I add two inches to cover the ear. I don’t see much point in wearing a hat that doesn’t keep your ears warm. Mine would run 8 inches from cuff bottom to top when finished. This is personal preference. Ask your guys where they want this hat to lie in relation to the ears. I would say minimum of 6 1/2 before you begin decreases. That’s a total height of 7. This won’t cover the ears but will be a fashionable hat.
These hats are designed to hug the head. You can either do a k1,p1 or k2,p2 rib for the bottom cuff. I do mine in all rib, but you can do one inch rib and the rest in stockinette.
I cast on 100 sts with a #5 needle, 96 sts with a #8 needle, or 52 sts with a #13 (best in a bulky weight yarn for this one.) I do mine in rib for 7 1/2 inches (to cover the ears), then begin the decreases. My decreases run about 1/2 an inch. Crown shaping: k2 tog, p2 together all around for the first row. K1,p1 all around for 3 rows. K2 tog all around for row 5. Cut yarn and draw through remaining loops. If you’re doing the top part of this hat in stockinette rather than rib, you’ll have all knit decreases rather than knit and purl.
This is not a copyrighted pattern, so please feel free to use it as you wish. This is my own tried and true pattern that seems to work for me. I use this for hats as well, just adding one or two inches extra for a fold up cuff. I like all-ribbed hats because they hug your head, don’t fall down over the eyes, and don’t twist around uncomfortably as you’re wearing them. I have adult sons that are very picky about everything. This is the only all-rib hat I make that they actually wear.
Here’s a couple links that might help, too.
Hat size chart -
http://community.knitpicks.com/notes/Size_Chart_-_Hats
Simple Hat Calculator -
http://www.earthguild.com/products/knitcroc/marypat/hatcalc.htm
I knit hats for charity and my standard is worsted weight yarn, CO about 80, length about 6-6.5" then decrease. Length can depend on your edge treatment… with a folded brim the length needs to be 2.5-3" longer.
Although mine are shorter than Cindys they do cover the ears.
I make the hats for charity - so can’t ask anyone for their preference/size. So just wanted a “standard” that would fit most. Sometimes I knit, sometimes crochet.
I’ve seen charts before that will say measure from top to bottom of unfolded cuff - wasn’t sure how much to subtract for the cuff (since a beanie doesn’t have a cuff). Nor how much to subtract if just the head circumference was given.
I agree, can’t see making a hat that doesn’t cover the ears - i.e. many of the hats/charities are for the homeless.
Much thanks for the replies.
I usually cast on 80 because it’s so easy to decrease when it’s a multiple of 10. However, I sometimes do cast on less, about 72 because I figure some people have small heads and then there’s women and younger people, too. I make them then try them on myself and my husband. If they fit us I figure they’re good. 
Here’s a pattern for basic charity hats for all ages. The rib stitch on these make them more adjustable for all sizes.
http://www.bevscountrycottage.com/bevs-basic-hat.html
Usually a stocking cap has about 2" worth of ribbing, then part or all of the cuff is folded up. So you could probaby knit to 1 to 2" less that a pattern says and start the decs. There’s tons of beanie hat patterns though which would have the right measurements - look at www.knittingpatterncentral.com and www.dailyknitter.com and search through the hat sections.