Q. In Chicago style after how many words do you use a block quote?

A. Please see CMOS 16, 13.10 (“Choosing between Run-In and Block Quotations”): “In deciding whether to run in or set off a quotation, length is usually the deciding factor. In general, a short quotation, especially one that is not a full sentence, should be run in. A hundred words or more (at least six to eight lines of text in a typical manuscript) can generally be set off as a block quotation.”