Used to ask about amount or price (How much?).
この時計はいくらですか。
How much is this watch?
今月の家賃はいくら払えばいいですか。
How much should I pay for this month's rent?
子どもはお菓子にいくら使ったの？
How much did the child spend on snacks?
A suffix after a rounded number meaning "and something" or "about ... and change."
値段は五千円いくらだった。
The price was about 5,000 yen and change.
今年の売上は一億円いくらに達した。
This year's sales reached about 100 million yen and change.
その時計は二万円いくらで売られていた。
That watch was sold for about 20,000 yen and change.
An adverb used in concessive expressions (e.g., いくら〜ても) meaning "no matter how..." or "however much...".
いくら頼んでも、彼は手伝ってくれない。
No matter how much I ask, he won't help.
いくら考えても答えが出ない。
No matter how much I think about it, I can't find an answer.
いくら忙しくても、休みは必要だ。
However busy you are, you need rest.