Buying bike helmet for daughter - how to measure?

Question

I'm trying to buy a bike helmet for my daughter online $20 or under. She's 8. She's had a couple - her last one was a Bell Youth. I'm finding there's all different shapes and styles and I don't know whether they indicate the outside, the inside, or if I can measure her head to compare. Then there's toddler, child and youth. Is child and youth the same or different? Any idea on how they determine the measurements in bike helmets? She's looking at a different style so I'm not sure how to compare. Any advice would be helpful. And if you have any opinions on good/bad bike helmets that would be helpful too. She likes to ride with no hands and stand on the bar of her bike...and we live on a steep hill...she likes to go fast...so a helmet is kinda important! Thanks! (her last one broke - that's why I'm steering towards a different style or kind). Oh ya, P.S. she has a lot of poofy hair...

Answer 1

They go by the INSIDE of the helmet...With a soft tape measure, measure her head around the fore-head. A child helmet will be smaller than a youth helmet.

  No such thing as a 'bad' helmet as they're required to pass certain tests...

I'd try to break her of careless riding though...It's a good way to end up in the ICU.