Calculate average word length in a text.
Average word length is letters per word, and it is one of the two inputs almost every readability formula uses. English general prose averages around 4.5 to 5 characters per word; academic and technical writing runs 5.5 or higher, largely because of Latinate abstractions and multi-syllable terminology. The share of words at seven characters or more is often more diagnostic than the average itself, since a handful of very long terms can lift the mean while the prose still reads plainly. Hyphenation is treated as an option because whether well-established counts as one word or two materially changes the figure on technical text.
Average word length
Average = total alphanumeric characters / number of words
Long word share
Share % = words of 7 or more characters / total words x 100
It depends on audience, not quality. General journalism sits around 4.5 to 5 characters, which suits a broad readership. Academic writing at 5.5 to 6 is appropriate for specialists. The number is only a problem when it is far above what your intended reader expects.
Because the mean hides distribution. Text with a 4.8 average could be uniformly plain, or plain prose punctuated by 14-letter technical terms — and those read very differently. The 7-plus character share is what most readability formulas actually key on.