also: ぐらい
Attaches to a quantity or time expression to give an approximate value. くらい and ぐらい are interchangeable, with ぐらい preferred after ん or voiced sounds.
It's about ten minutes on foot to the station.
This luggage weighs around five kilograms.
to the extent that; so ... that ...; at least
Follows a verb or adjective to indicate the degree or extent of an action or state, often implying a noteworthy result. Can also express a minimal degree ('at least').
I was so happy I almost cried.
At least that much I can do too.
as ... as ...; like
Used in comparisons to equate the degree or manner of one thing with another. Often follows a noun or clause.
There is no one as kind as him.
If you're as old as you are, you should be more responsible.
I bought about three apples.
I was so happy I could have cried.
There's no one as kind as him.
I'll leave home at around ten o'clock.
くらい can follow almost any quantity or expression to mean 'approximately', while あたり is more naturally used after specific numbers or times.
くらい is freely used to express approximation of amount or degree, whereas ら's approximate sense is limited to fixed words like ここら and そこら.
くらい is a more common and versatile suffix for approximation, while 通り in this sense is less frequent and more formal, mainly appearing after fractions like 九分.
くらい marks an approximate amount or quantity (and can loosely mark time too), whereas 頃 is specifically used to mark an approximate point in time.
くらい is a casual way to say 'about/approximately', whereas 程度 sounds more precise and is common in written or technical Japanese.
medium; middle; average