〜ほど

to the extent / not as…as

Shows degree: "so…that", "to the point of…". With a negative, it compares: "not as…as X".

Readings

How to form it

After a verb or adjective, ほど shows how far something goes: 泣(な)きたいほど悲(かな)しかった (I was so sad I wanted to cry).
Noun + ほど with a negative means "not as…as": 今年(ことし)は去年(きょねん)ほど寒(さむ)くない (this year isn't as cold as last year).
Noun + ほど〜はいない (or はない) means "no one (nothing) is as…as": 彼(かれ)ほど頭(あたま)がいい人(ひと)はいない (no one is as clever as him).
After a number, it means "about": 三十分(さんじゅっぷん)ほど (about thirty minutes).

泣(な)きたいほど悲(かな)しかった。

I was so sad I wanted to cry.

彼(かれ)ほど頭(あたま)がいい人(ひと)はいない。

Nobody is as clever as him.

Using ほど for a positive comparison. Say 今年(ことし)は去年(きょねん)より寒(さむ)い (colder than last year).

〜くらい / 〜ぐらいabout / at least
"About" or "at least"; also shows degree, a little more casually.
よりthan
"Than" in a positive comparison.