how to convert iq test score to mental age

I think you may be confused, what do you mean by "iq level"?

I'm more interested in what he means by "mental age." IQ is fairly well defined; I've never heard the term "mental age."


The original definition of IQ was based on the rate at which a child developed skills compared to the norm. If it is normal to read by 5, and a child was reading by 2 1/2, then that child would have been said to have a 200 IQ.

IQ measurement has changed dramatically, however.

Edit: Whoops. Just re-read the actual post instead of the thread title. Yeah, I don't know what the author means by "IQ level" or "mental age."

Mental age
From Wikipedia, the free encyclopedia
Mental age is a controversial concept in psychometrics. It is an intelligence test score, expressed as the chronological age for which a given level of performance is average or typical.

How mental age is used to derive an IQ score
After taking a standardized test, an individual's mental age is divided by his chronological age and multiplied by 100, yielding an intelligence quotient (IQ). Thus, a subject whose mental and chronological ages are identical has an IQ of 100, or average intelligence.

Louis Leon Thurstone was among prominent critics, stating "The Mental Age concept is a failure in that it leads to ambiguities and inconsistencies." This criticism however mainly focused on the use of mental age concept for adults. Mental age is nowadays used for monitoring children's educational progress and is seldom expressed as an IQ score.

I'm not sure about the question which is being asked here. The title of the thread refers to Mental Age, but the post asks about I.Q. level.

Let me just say that I.Q. scores are those scores which are obtained on specific tests of intelligence. The scores are considered valid and reliable only for those particular tests. So, when discussing I.Q., you should always refer to the specific test used to obtain that I.Q. score.


The term "Mental Age" refers to certain scores obtained on Stanford-Binet tests of intelligence which are then used in computing the individual's I.Q. score on those tests. If an I.Q. score has been obtained using a Stanford-Binet test, you already have that individual's Mental Age score, on that test, and no further conversion is involved. The Stanford-Binet test manual contains the information showing degree of correspondence between I.Q. scores and M.A. equivalents.

In the United States, the most widely used individually administered intelligence tests are the various Wechsler scales/tests (WAIS III, WISC IV, etc). The Wechsler tests do not yield a Mental Age score, although a Test Age score can be obtained.

By I.Q. level, do you mean the range within which a particular I.Q. score falls relative to the general population?

The ranges on the several Wechsler tests which measure intelligence or mental ability are as follows--for I.Q. scores derived from Wechsler tests (i.e. WAIS III, WISC IV):

Below 70 Extremely Low range

70-79 Borderline range

80-89 Low Average range

90-109 Average range

110-119 High Average range

120-129 Superior range

130 and above Very Superior range

Again, to be most accurate, these ranges pertain only to I.Q. scores obtained on Wechsler tests/scales of intelligence. They indicate where a particular I.Q. score falls relative to the general population on that test.

Does that answer your question?

well, i copied an iq test questions from the internet. if a let a man answer it and took a 30 item test and scored 20 out of 30 within 30 minutes with an age of 17 and a test mean of 15, how can i turn the score into the numbers in the scale?

harru, I'd be very skeptical about the validity of any so-called I.Q. test that you find on the internet. These tests may be fun to take, but I wouldn't put much faith in the scores, at all.

The most "accurate" intelligence tests are those that are individually administered and scored by a psychologist. Since you must take these tests in person, the results cannot be duplicated by anything you would find on the internet.

Group tests, which are the only types of tests you can find on the internet, are tests which can be given to large groups of people, they are self-administered (you read the questions by yourself and respond without an examiner present) and generally are automatically scored by the Web site. These really should not be considered as meaninfgul tests of intelligence. The best of these tests might be screening devices to give you some idea of your aptitude when compared to other people who might take this test. However, the validity of these tests is open to serious questions. How do you know this test is actually measuring what it claims to be measuring?
The business of test construction is quite complicated, and if a test cannot demonstrate that it measures what it purports to measure, it is of no value at all. Abilities and aptitudes can also be heavily influenced by cultural factors--a test constructed to measure something in one group of people may not yield similar results when given to a different cultural group. Group tests, of a type found on the internet, cannot control for these cultural factors because there is no way of establishing the identity of those taking the test. You may also know next to nothing about the qualifications of the person who constructed the test, or how it was standardized.

Any group test you find on the internet, claiming to measure intelligence or I.Q., should be taken only for fun or entertainment value--and do not place too much importance on the scores, because they are not likely telling you very much, and they may bear little relationship to an I.Q. score you might get on an intelligence test individually administered and scored by a psychologist.



Based on that info, I can't answer your question. You have the mean score, but not the standard deviation from the mean. Just knowing that a score of 20 is 5 points over the mean really doesn't tell you much, other than that your score is allegedly above the mean, or average, on that particular test.

You cannot get a valid Mental Age or I.Q. score from this type of test--a score that would be comparable to that obtained from the Stanford-Binet or Wechsler tests of intelligence.

But, the Web site where you found the test questions should provide you with the info to find out what that your "score" is on this particular test, and how it might compare to others who take this particular test. As I said, regard this info with a grain of salt and a great deal of skepticism.

If you post a link to the site where you obtained the questions, I'll see if I can help you figure out your score, or range, on that particular test.

for finding out your mental age all you have to do is to obtain the product of your chronical age and divide it by 100.
for example,if your age is 10 and your IQ score is 120,then your mental age will be:
120*10/100=12
it simply means you have the mental capability of a person of age 12.

IQ tests doesn't really relate much to Mental Age tests.

Imo not convertable, and shouldn't be considerd.