How many letters does the top answer for “a small piece or quantity of something” have?

The most common answer is bit (3 letters).

Crossword clue: a small piece or quantity of something

1 answer found in Letterora's clue database (Wikidata facts, Open Trivia DB, WordNet and Webster definitions — all licensed sources).

bit 3 letters wn-def

a small piece or quantity of something

the act of breaking something into small pieces 50% similar → shattering, smashing