how much; how many; to what extent
Used to ask about degree, quantity, or extent. Can be used as an adverb or noun.
no matter how much; however
Used in concessive patterns like どれほど...ても/でも to mean 'no matter how much' or 'however'.
(not) much; (not) many; hardly; barely
Used with どれほども and a negative verb to mean 'not much/many' or 'hardly any'. Often implies a small amount or almost none.
How much time will it take?
Do you understand how much he feels?
No matter how hard I try, I can't beat him.
However expensive it is, I want to buy it.
There is hardly any left.
I got tired after walking barely any distance.
どれほど is more formal and literary than どれだけ, and tends to appear in written or formal speech rather than casual conversation.
どれほど is more literary or formal than どのくらい, often appearing in written language or polite speech rather than everyday conversation.
どれほど is the question form asking 'how much/to what degree,' while それ程 states an already-known degree, often 'that much (and no more).'
Kanji spelling using 程; less common but still encountered.
Rare kanji form; may be confused with なにほど.
Very rare kanji form; not recommended for learners.
Compound of どれ (interrogative) and ほど (extent, degree). The kanji forms are ateji.