MBTI type percentages: the most common and rarest types in Korea and the US

Search for how common each MBTI type is in Korea and every table seems to give a different number. Even among figures with a named source, ISTJ comes out at 11.6% in the US representative sample, 12.8% in ASSESTA’s Korean distribution and 24% in a sample of software engineers. Gaps like these usually do not mean someone made a mistake; they mean the tables counted different people with different tests. This guide keeps only figures whose source can be named, shows which types are common and rare in Korea and the United States, and explains what to look at before trusting a percentage.

One term first. A representative sample is drawn so that its mix of sex and age matches the actual population. Unlike an online tally of people who chose to take a test, it is designed for estimating shares across a whole population. Even so, it is an estimate made at one time with one instrument, so the broad pattern matters more than each decimal.

The short answer: in both the Korean and the US data, types that combine Sensing (S) and Judging (J) were common and INFJ was the rarest. That does not make common types more normal or rare types more special. A percentage describes who gathered in a sample, not who you are.

The best-documented Korean data come from a 2021 study by Song, Park, Kang and Kim in Psychological Type & Human Development, the journal of the Korea Academy of Psychological Type. From official MBTI (Form M) responses collected between 2012 and 2020, the authors drew 19,070 people aged 16 to 59 (9,705 men and 9,365 women) so that the age and sex mix matched Korea’s population. In that sample ISTJ was the most common type and INFJ the least common, and the spread of the four preferences differed by age. One limit remains: the sample was still drawn from people who had taken the official assessment.

Type-by-type figures are best known from a distribution released by ASSESTA, the official distributor of the MBTI in Korea, as reported by the Korean press in January 2023. From most to least common: ISTJ 12.8%, ESTJ 12.4%, ENFP 9.7%, ISFJ 8.3%, ESFJ 8.2%, ESFP 7.2%, INFP 6.7%, ISFP 6.5%, ESTP 4.2%, ISTP 4.1%, ENTP 3.6%, ENTJ 3.5%, ENFJ 3.3%, INTJ 3.3%, INTP 3.2% and INFJ 2.9%. The report gives no sample size or survey period, but the most and least common types match the study above.

Adding the table up by preference shows the shape of this distribution. Sensing types make up about 64%, far more than Intuition types (about 36%), and Judging is a little ahead of Perceiving at about 55%. Extraversion and Introversion sit near 52 to 48, and Thinking and Feeling near 47 to 53. ISTJ and ESTJ alone add up to 25.2%, about one person in four. These totals are mind.io’s sums of the rounded published figures, so the decimals may differ slightly from the original data.

For the United States, the most cited figures come from the national representative sample of 3,009 people in the third edition of the MBTI Manual (Myers, McCaulley, Quenk and Hammer, 1998). From most to least common: ISFJ 13.8%, ESFJ 12.3%, ISTJ 11.6%, ISFP 8.8%, ESTJ 8.7%, ESFP 8.5%, ENFP 8.1%, ISTP 5.4%, INFP 4.4%, ESTP 4.3%, INTP 3.3%, ENTP 3.2%, ENFJ 2.5%, INTJ 2.1%, ENTJ 1.8% and INFJ 1.5%. These numbers are taken from a peer-reviewed paper that reproduces the manual’s table (Capretz, 2003), and The Myers-Briggs Company, which publishes the assessment, also describes INFJ as the rarest type at 1.5% of the US general population.

By preference, the US sample leans even further toward Sensing than the Korean one, at 73.3%. Feeling (59.8%) outnumbers Thinking (40.2%), Extraversion (49.3%) and Introversion (50.7%) are close to even, and Judging stands at 54.1%. These preference shares come from the publisher’s 2016 technical brief, which reprints the same representative sample.

Side by side, the two countries share more than they differ. In both tables the SJ types (ISTJ, ISFJ, ESTJ, ESFJ) fill the top of the list, together 41.7% in Korea and 46.4% in the US, and INFJ is the rarest. The differences: in the US the Feeling SJ types ISFJ and ESFJ take first and second place, while in Korea the Thinking SJ types ISTJ and ESTJ do. ENFP also ranks higher in the Korean table (third, 9.7%) than in the US one (seventh, 8.1%). The two data sets differ in when they were collected, in language edition and in how the samples were drawn, so these gaps are hard to read as national character.

First, different people take part. An online test site’s tally describes the people who came to that site and finished the test. If many of them are keen on personality types, came from one community that shared the link, or belong to one age group, the percentages tilt that way. The MBTI publisher itself reported that in a convenience sample of 3,836 mostly employed New Zealanders, ENTJ was more than four times as common as in the US representative sample, and stated plainly that such a sample cannot be used to infer the type distribution of the country’s population.

Second, they are not the same test. The official MBTI, free MBTI-style tests online and 16Personalities each use different questions and scoring. The same person can get different results on them, so comparing percentages counted with different tests tends to show bigger gaps. The MBTI accuracy guide covers those differences in detail.

Third, it depends on which group was surveyed and when. The Korean study above found that the spread of the four preferences differs by age. Occupational groups can differ even more: in a study of 100 software engineers (Capretz, 2003), ISTJ made up 24%, more than twice the 11.6% in the US representative sample. “Many developers are ISTJ” and “many people are ISTJ” are different claims.

Fourth, borderline results are folded in. Someone whose answers on one preference came out nearly even can easily get a different letter on a retest. A percentage counted from a single test includes which way all those near-even people happened to fall that day. The four MBTI preferences explains how to read a near-even result.

Calling a type rare only means that few people in that sample were sorted into it. Rare does not mean smarter or more special, and common does not mean ordinary or less interesting. The MBTI asks which way you prefer, not how good you are, so type percentages say nothing about the worth of a personality.

Which type counts as “the rarest” also depends on the source. Both the Korean study and the US representative sample put INFJ last, yet tables circulating online sometimes present another type, such as ENFJ, as the rarest. In the Korean distribution released by ASSESTA, ENFJ is at 3.3%, level with INTJ and slightly above INTP (3.2%) and INFJ (2.9%).

A type that seems to be everywhere on social media may be a similar illusion. People who enjoy talking about types tend to mention their own type more often, and those posts may travel further. The types you see most often are not necessarily the most common ones. For the “most sensitive MBTI type” lists you often see there, our guide to sensitivity and MBTI types looks at what the research says.

If your result came out rare, read it as “my way of doing things may be less common around me” rather than “few people will understand me.” If it came out common, people of the same type still differ quite a lot. If you are torn between two types a letter apart, look-alike MBTI types compares similar types side by side.

mind.io also has an MBTI type ranking. It collects, anonymously, only the result types of people who tapped the join button on their own result page, and shows them in order. What is sent is the test, the result type and the page language; answers, scores and names are not. IP addresses and cookies are not read either.

This ranking is not a population share. It reflects people who found mind.io, finished the test and chose to join, so it is the kind of self-selected sample described above, and the numbers count entries rather than people; entries are anonymous and unverified, so automated ones may be mixed in. The mind.io MBTI test is also not the official MBTI but a free test that asks about the same four preferences. It is natural for the ranking to look different from the survey data above.

The ranking stays hidden until 80 entries have come in, because with only a handful of entries one or two results could change which type comes first. Comparing the survey figures with the ranking lets you see how “people in general” differ from “people interested enough in the MBTI to take a test themselves.”

Q. What is the most common MBTI type in Korea? A. Both the Korean representative-sample study (Song and colleagues, 2021) and the distribution released by ASSESTA put ISTJ first. In the ASSESTA figures ISTJ is at 12.8%, barely ahead of ESTJ at 12.4%.

Q. What is the rarest MBTI type? A. INFJ. It was the least common type in the Korean representative-sample study; it is at 2.9% in the ASSESTA distribution and 1.5% in the US representative sample. Online tallies sometimes name a different type, usually because their participants are self-selected.

Q. Is it true that one in four Koreans is ISTJ? A. In the Korean distribution released by ASSESTA, ISTJ is at 12.8%, about one in eight. ISTJ and ESTJ together come to about one in four (25.2%). Whatever the table, check who was surveyed and how before relying on the numbers.

Q. Does a rare type make me special? A. Rare only means few people in that sample were sorted into the type; it says nothing about which personality is better. Common and rare types each have their own strengths and struggles.

Q. Why does the mind.io ranking differ from these tables? A. The ranking shows people who took the test on mind.io and chose to join, using a test that is not the official MBTI. It answers a different question from a representative sample, which estimates population shares.

References: Song, Park, Kang & Kim (2021), The Study on the MBTI Type Distribution in the Korean National Representative Sample Based on 2012-2020 Data, Psychological Type & Human Development 22(2), 19-41, https://doi.org/10.52745/KAPT.2021.22.2.19; Insight (Korean news site), report on ASSESTA’s MBTI type distribution (7 January 2023), https://www.insight.co.kr/news/425441; Myers, McCaulley, Quenk & Hammer (1998), MBTI Manual (3rd ed.), Consulting Psychologists Press; Capretz (2003), International Journal of Human-Computer Studies 58, 207-214; CPP (2016), Technical Brief for the MBTI Form M and Form Q Assessments—New Zealand; The Myers-Briggs Company, What is the least common Myers-Briggs personality type? (2017) (all accessed October 2026).