I still think it's 18 for the UK.

16 and you're the legal age for sex and marriage.
17 and you can legally drive.
18 and you can drink.

Although you can live on your own, get a job and leave full time education at 16, I don't think we're considered adults until we're 18.

Which is fine by me. Means I've still got 9 months of free dental checks and eye tests.