Answer: 50 characters is between 7 words and 13 words with spaces included in the character count. If spaces are not included in the character count, then 50 characters is between 8 words and 17 words.
According to research by Miller, Newman, and Friedman, "the average length of a function word was 3.13 letters; for a content word the average was 6.47 letters." To get the estimates above, we assumed that words in sentences range from 4-7 letters. We also assumed that sentences have 15-20 words and paragraphs typically have 100-200 words and 5-6 sentences.
What Counts