Free IQ Test.

It gives a solid estimate, not an official score. Every question has a difficulty rating, and your result is worked out from which questions you answered correctly using item response theory — the same family of methods behind professional tests — so hard questions count for more than easy ones. It isn’t a clinical assessment, though: only a supervised test such as the WAIS, given by a psychologist, can give you an official IQ. Treat your result as a good indication, and expect it to move by a few points between attempts, which is why a likely range is shown alongside it.

IQ scores are scaled so the average is 100. About two-thirds of people score between 85 and 115, and about 95% score between 70 and 130. Anything from 110 up is above average, 120 or more is very high, and 130 or more puts you in roughly the top 2% of the population.

When you finish, the page estimates your ability from your pattern of right and wrong answers, taking each question’s difficulty into account and allowing for lucky guesses. That estimate is converted to the standard IQ scale (average 100, standard deviation 15), and your percentile is the share of people you’d be expected to outscore. The difficulty ratings are careful estimates rather than figures from a formal norming study, so treat the result as an estimate rather than a precise measurement.

The standard test has 20 questions and a 15-minute limit — most people finish in about 10 minutes. The quick test has 10 questions and an 8-minute limit, and takes about 5 minutes. The standard test gives a more precise result because it has twice as many answers to go on.

Yes, as often as you like. The puzzles are generated fresh for every attempt, so you won’t get the same questions twice. Scores often rise a few points on a second try simply because the puzzle types feel familiar, so your first attempt is usually the fairest measure.

IQ tests measure how well you solve unfamiliar problems, and working against the clock is part of that — given unlimited time, most people could eventually work through every puzzle. The limit is generous and most people finish with time to spare. Unanswered questions count as wrong, so it’s worth making a guess before the time runs out.

No. High-IQ societies such as Mensa only accept results from supervised tests, so no online test can be used to join. This test is for your own interest — though if you score 130 or more, a supervised test might be worth a try.

It’s designed for adults and older teenagers. Children’s IQ scores are worked out by comparing them with other children of the same age, which this test doesn’t do, so a child’s result here wouldn’t mean the same thing.

No. The puzzles are created and marked right here in your browser tab, on your device, so your answers are never uploaded and nobody asks for your email. If you leave part-way through, your progress is saved on this device so you can resume, and your last score is remembered here so you can compare next time. See the Privacy Policy for details.