How it works

What it measures

The test places you on six scales: where your energy comes from, how you take in ideas, what weighs most when you decide, how you approach plans, how you handle pressure and whether you cope with others or on your own.

Each scale has two poles, and neither is better. Your letter is the pole you lean toward.

How it relates to the MBTI

The MBTI sorts people on four scales. Research comparing it with the Big Five, the most studied model of personality, found that each MBTI scale lines up with one Big Five trait: E/I with extraversion, S/N with openness, T/F with agreeableness and J/P with conscientiousness (McCrae and Costa, 1989).

This test measures the four letters with Big Five statements, then adds two scales the MBTI does not have: how steady you stay under pressure, and whether you lean on others or handle things yourself. That makes six letters and 64 types.

Where the statements come from

65 of the 72 statements come from the International Personality Item Pool (IPIP), a public collection of more than 3,000 statements started by Lewis R. Goldberg at the Oregon Research Institute and used in research for over 25 years.

For each of the first five scales, we started from the 300-statement IPIP-NEO inventory and kept the 12 statements that agreed best with the rest of their scale across more than 135,000 real answer sheets. The sixth scale combines five IPIP-HEXACO statements with seven new ones, which are still being calibrated.

Who you are compared with

Your score on each scale is compared with a reference group of more than 135,000 people who took the IPIP-NEO online and shared their answers for research (Johnson's IPIP-NEO data, Open Science Framework). Only complete answer sheets from people aged 16 or over were kept, with duplicates removed.

The group leans young (median age 22) and is 58% women. If you are much older, your percentiles compare you with a younger crowd.

How a letter is decided

Your answers on each scale are compared with the reference group. The letter says which side of the middle you landed on.

Answers carry some noise, so each scale also shows the range you would likely land in if you took the test again.

How often a retake agrees

We checked this on 60,000 real answer sheets. The statements for each scale were split into two equivalent sets, and we counted how often the same person landed on the same side in both.

With 12 statements per scale and five answer options, the estimate is about 81% for each letter. Formats common on free MBTI sites did worse, even when built from the same research statements: five yes-or-no questions per letter came out at about 65%, two questions per letter at about 62%.

Both sets were answered in one sitting, so a real retake weeks later agrees somewhat less. That is why close calls are shown as in-between instead of forced: with that rule, about 7 in 10 people would see none of their clear letters flip to the opposite side.

Close calls

When a scale lands near the middle, the test asks a few more statements on that scale before deciding. If it is still close, the result says you are in between instead of forcing a side.

What it is not

This is a tool for self-understanding. It is not a clinical assessment and should not be used for hiring or diagnosis.

It is an independent project, not affiliated with The Myers-Briggs Company or 16Personalities.