IQ 63

On the standard scale, 63 sits 37 points under 100. You scored higher than 0.68% of people, and about 1 in 147 people score at this level or lower. It sits 7 points below 70. The label for this part of the curve is Below Average.

A score under 70 on a single online test does not mean anything clinical. Only a qualified professional, such as a clinical or educational psychologist, can assess that, using supervised tests and a look at everyday functioning.

Plenty of valuable skills are learned mainly through practice. Trades, care work, hospitality, sport, driving and music all reward repetition and experience, and people keep improving at them for decades.

Retest gains of a few points are well documented once a format is familiar. First attempts at any unfamiliar kind of test tend to be the least representative.

Online scores are estimates with wide error bars. For 63, a 5-point window either way runs from about 58, where 1 in 391 score that low or lower, to 68, where it is 1 in 61.

Professional assessments combine several subtests (verbal, visual, memory and speed) and look at the pattern between them, not just one total. A single online total cannot show that pattern.

Time limits matter. Some people reason accurately but slowly, and a short, timed test turns that into a lower number than an untimed task would.

The same person can score 58 one week and 68 the next. Most of that swing comes from the conditions on the day rather than any change in ability:

• Sleep. A short night reliably hurts working memory and attention, the two things timed puzzles lean on hardest.
• Familiarity. People who have seen matrix-style puzzles before tend to do better on them. That is a practice effect, not a change in underlying ability.
• Timing and comfort. Hunger, a headache or testing late at night can all pull a score down on the day.

If IQ follows the standard bell curve, 0.7% of people score 63 or lower. Here is what that share means across whole populations:

Scoring 63 or lower is about 1 in 147. At 68 or lower it becomes 1 in 61, and at 58 or lower 1 in 391, which shows how quickly the curve fills up towards the middle.

What your 63 could really be. Even a good supervised test has a margin of error of roughly 5 points either side. A true score anywhere from 58 to 68 would be consistent with a 63, which spans the 0.26th to the 1.6th percentile. Short online tests have wider margins.

Which scale was it on? A 63 reported on an SD 16 scale converts to about 65 on the usual SD 15 scale, and one from an SD 24 scale (seen in some Cattell-style results) to about 77. Check which scale your score report used.

Nobody famous has a verified IQ in most cases, and retrospective estimates are only made for a narrow group.

No historical figure on this site has an estimate close to 63. Retrospective estimates cluster between about 115 and 250 because they are only made for people with exceptional achievements. That is a selection effect, not a sign that famous or successful people cannot score 63.

The scores one and five points either side of 63, plus the round numbers from 100 to 150, side by side. Tap any score for its full page.