Guides
Plain explanations of IQ and IQ tests. Every number on these pages comes from a cited source or from the math of the scale itself.
Want your own number? The test is 25 visual puzzles, about 12 minutes, no sign-up.
Start here
- 01What does an IQ test measure?Reasoning, general ability, and the parts a score leaves out.
- 02The IQ bell curve, explainedMean 100, standard deviation 15, and what a percentile really says.
- 03What is the average IQ?100 by design. What the average range covers and why.
- 04How to read an IQ scoreThe score, the range, the percentile, the label and the scale.
- 05IQ classification, band by bandSeven labels, their ranges, and how many people fall in each.
- 06How online IQ tests workFrom answers to an estimate, and how to tell a careful test from a toy.
The puzzles
- 01Matrix reasoning, explainedHow 3x3 matrix puzzles are built, and how to read them.
- 02Pattern recognition on IQ testsSequence puzzles, the rules they hide, and the usual traps.
- 03Spatial reasoning, explainedMental rotation, mirror images and the odd one out.
- 04How to solve number series questionsThe rules behind number series, and a method that finds them.
- 05How to solve figure analogiesA is to B as C is to what? The changes and how to spot them.
- 06Culture-fair IQ testsShapes instead of words, and what that can and cannot promise.
The ideas behind IQ
- 01What is the g factor?Spearman's general ability, and why different tests agree.
- 02Fluid vs crystallized intelligenceReasoning with new problems versus using what you already know.
- 03A short history of IQ testsFrom Binet in 1905 to WAIS-5 in 2024.
- 04WAIS, Stanford-Binet, Raven's and Mensa tests comparedWhat each major test measures, and why the numbers differ.
Try one · Spatial Reasoning
Which option is the same shape, only rotated?
Tap the option you think is right, or show the answer.
Show the answer
Option 1 is the original figure turned a quarter turn clockwise.
How to solve it
- Pick a landmark: the marked cell or the end of the longest arm.
- Turn the figure in your head and watch where that landmark goes, and which side the other cells end up on.
- Turning the figure a quarter turn clockwise gives option 1.
- Each of the other options is a mirror image: flipping it over would match, but no turn does.
That was 1 puzzle. The full test has 25.
Research and change
- 01What IQ predicts, and what it does notGrades, jobs and income: what the correlations say and do not.
- 02The Flynn effectWhy measured IQ rose for decades, and what it means for your score.
- 03IQ and ageDifferent abilities peak at different ages. The score is age-normed.
- 04How to prepare for an IQ testWhat practice changes, what it does not, and what actually helps.
Comparisons
- 01Online vs clinical IQ testsWhat each kind of test is for, and when you need which.
- 02Free vs paid IQ testsWhat each model pays for, and what to check before you start.
- 03IQ test vs aptitude testGeneral reasoning versus readiness for a specific job or course.
- 04WAIS vs Stanford-BinetAges, structure, timing and scoring, side by side.
- 05CogAT vs NNATTwo school ability tests, side by side.
- 06Wonderlic vs CCATFifty questions, a short clock, and how each is scored.
More ways to learn
- 01IQ questions, answeredShort, sourced answers to the most asked IQ questions.
- 02IQ glossaryThe terms behind IQ scores, defined in plain English.
- 03IQ puzzles with answersSix puzzle types, easy to hard, every one solved step by step.
- 04Free practice testsTen timed questions, an instant practice score, no sign-up.
Scores and tools
- 01IQ score chartPercentile, rarity and classification for every score.
- 02IQ by percentileThe IQ at the top 1%, 2%, 5%, 10% and more, on three scales.
- 03IQ percentile calculatorAny IQ score to percentile, rarity and classification.
- 04Percentile to IQ converterAny percentile to the matching IQ on three common scales.
Free tools: IQ percentile calculator · Percentile to IQ converter · IQ score chart
25 puzzles · about 12 min
Find your IQ in 12 minutes.
25 visual puzzles, free to take. Your full result, with your estimated IQ, percentile and five-area breakdown, is $4.95 one time.
Free to take. Full result $4.95, one time. No subscription.