Several studies over the years have tried to determine the average vocabulary size of adults and children. In 2013, The Economist published an article that estimated that adult native test-takers knew about 20,000 to 35,000 words and a native 8-year old will usually have an average vocabulary of 10,000. They also found that vocabulary size stops growing at mid-age.
Another study by UPI.com in 2016 estimated that actually “most U.S. adults have a vocabulary of more than 42,000 words” at age 20 and up to 48,000 by age 60.
A number of other studies have been done to determine how many words an average person knows. The difference in all of these estimates is due to several factors since there have been slight differences between the studies.
For instance, in some cases, the words and their derivatives were considered to be unique words. Therefore, “fall” and “fell” would be considered to be two different words. In other studies, however, only the head word was considered, which means “fell” would not be considered a separate word since it is derived from “fall.”
So, how many words does the average person know?
1. Education and vocabulary level
In consideration of these two viewpoints, it was discovered that a highly-educated native speaker has a vocabulary of about 10,000 words when only the head words are considered.
2. Amateur speakers vs seasoned speakers
A beginner who has just had a week or so of learning a language usually has a vocabulary of about 250 to 500 words. This is usually enough vocabulary to communicate as a tourist and have simple everyday conversations.
But to make it through scenarios like shopping, travel, and tell and ask people about their days, a vocabulary of about 1,000 to 3,000 words.
3. Advanced speakers
After getting to a vocabulary of between 4,000 and 10,000, you are quite advanced in the use of that language. With a knowledge of these words, you can talk about professional fields, use more complex words in regular conversations, and even do pretty well in language tests.
4. Fluent Speakers
If you think that you are fluent in the use of a certain language, then it’s because you know 10,000 words or more. This language level is described as being “near native.” At this stage, you can also understand unfamiliar words based on other words in the sentence because you will understand most of them.
5. Native Speakers
For native speakers, the amount of words mastered ranges from 10,000 to more than 30,000 words. However, this can vary depending on the language, as some languages do not have as broad a vocabulary. For instance, the English language has a lot of words, and average native speakers might know as many as 65,000 words.
Vocabulary Size and Age
However, even among native speakers, the number of words mastered ranges considerably based on age.
The reason natives manage to learn so many words is that they learn over a much wider period of time. On average, adults learn one new words every day until they reach their middle ages.
Foreign speakers usually have a vocabulary of about 4,000 words. However, living abroad can more than double this figure as they tend to master 2.5 new words every day simply because they are living in a country that speaks the language.
For instance, the average 20-year old American has knowledge of 42,000 words. However, those on the higher end of the spectrum know over 50,000 words.
Want to test your vocabulary?
If you want to try your vocabulary chops, try playing the game that The Economist study is based off of: TestYourVocab.com. See how high you can score!