"Most of us assume Psalms is the longest book in the Bible, since it has 150 chapters. In your recent Bible quiz, however, you listed Jeremiah as the longest book. Are you sure about that?" - J.T.
It’s not the number of words, or verses, or chapters – but the actual space displaced in a Bible (though not counting the empty spaces). Please find out the number of Hebrew letters in each of the two books. I think that will give you the certainty you are seeking.
"Thank you for the quick and informative reply. So, I had trouble finding the number of letters, but I found a site that listed "bytes," and I think that might be letters, or close to it. They have:
"So Jeremiah it is! Thank you for the enjoyable quizzes - even the trivia questions."