YOU SAID:
You have no idea how much you're going to need it.
INTO JAPANESE
どれくらい必要になるかわかりません。
BACK INTO ENGLISH
I don't know how much I'll need.
INTO JAPANESE
どれくらい必要か分かりません。
BACK INTO ENGLISH
I don't know how much I need.
INTO JAPANESE
どれくらい必要か分かりません。
BACK INTO ENGLISH
I don't know how much I need.
That didn't even make that much sense in English.