Why Common Words Are Short: Word Length vs Frequency in 18,745 Words
The most-used words in English are short. In our list, words used more than 1,000 times per million words average just 3.8 letters. Words used fewer than once per ten million average 8.3 letters. Every step down in frequency adds length.
Key facts
- Most frequent group (19 words): 3.8 letters on average.
- Rarest group (5,650 words): 8.3 letters on average.
- Easy words average 6.3 letters and 2.0 syllables; hard words 8.0 letters and 2.8 syllables.
- Researchers have linked word length to how predictable a word is, not only how often it is used.
The numbers
We grouped every word by its Zipf frequency, a scale where 3 means about once per million words and each step is ten times more or less often.
| How often the word is used | Words | Average length |
|---|---|---|
| Less than 1 per 10 million | 5,650 | 8.3 letters |
| 1 per 10 million to 1 per million | 9,160 | 7.6 letters |
| 1 to 10 per million | 3,274 | 6.8 letters |
| 10 to 100 per million | 642 | 5.5 letters |
| More than 100 per million | 19 | 3.8 letters |
Zipf’s law of abbreviation
The linguist George Kingsley Zipf noticed this in the 1930s: the more often a word is used, the shorter it tends to be. It shows up in language after language. It makes sense as a kind of efficiency. If you say something hundreds of times a day, a short form saves effort, and words like “bus” (from omnibus) and “phone” (from telephone) got shorter as they got more common.
Predictability matters even more
In 2011, Steven Piantadosi, Harry Tily and Edward Gibson at MIT tested this across 11 European languages and found that how predictable a word is from the words before it explains word length better than raw frequency. In English, information content accounted for about 9% of the variation in length, compared with about 1% for frequency. Words that carry a lot of new information tend to be longer, giving listeners more signal exactly where they need it.
What it means in practice
- For games like Pictionary and Hangman, shorter words are generally easier, so start with the easy words generator for kids.
- For a word puzzle with a fixed length, try the 5-letter or 7-letter word generators.
- For vocabulary building, long words are not automatically hard: straightforward (15 letters) is common, while gnu (3 letters) is rare.
Sources
- Our own analysis: 18,745 words, frequency from wordfreq.
- Piantadosi, S. T., Tily, H. and Gibson, E. (2011). Word lengths are optimized for efficient communication. PNAS 108(9). Summary: MIT News.
- Zipf, G. K. (1935). The Psycho-Biology of Language. Houghton Mifflin.
