How this spatial reasoning test works
This is a mental rotation test. Press Start test and you see two flat shapes side by side, each made of six squares. The right shape is always the left one turned by some angle. Your job is to decide:
- Same: the right shape is the left shape, only rotated.
- Mirror: the right shape is the mirror image of the left shape, then rotated.
You answer with the two buttons, or with the keys 1 (Same) and 2 (Mirror). There are 20 pairs: 10 of each kind, in random order. The turn between the two shapes is a multiple of 45 degrees, from 45° up to 315°, and the left shape itself also starts at a random angle. After each answer the frames flash green (correct) or red (wrong), and the next pair appears. Rule-finding puzzles of another kind, 3 × 3 grids with a missing piece, are in our IQ test.
Every shape is generated in your browser for that run, so you never see the same set twice. The generator only keeps shapes that are chiral, meaning no amount of turning can make the shape match its own mirror image. That guarantees every question has exactly one correct answer.
How to read your score
Your score is the number of correct answers out of 20. The result card also shows:
- Accuracy: correct answers as a percentage.
- Average per correct answer: how long you took on the pairs you got right, in seconds.
- Total time for the whole run.
Because there are only two choices, pure guessing scores about 10 out of 20. The card uses simple bands: 18 or more, 15–17, 12–14 and under 12. These are labels for this test, not norms from a study. We do not show a "typical" score, because published mental rotation studies use different shapes, angles and time limits. Your personal best and recent results are saved in this browser.
Speed and accuracy pull against each other. If you answer in a fraction of a second, you are probably guessing; if you take ten seconds per pair, you will be accurate but slow. Compare your runs with a similar pace.
The science: Shepard and Metzler
Mental rotation became a classic experiment in 1971, when Roger Shepard and Jacqueline Metzler showed people pairs of drawings of three-dimensional block figures. As here, each pair was either the same object turned, or a mirror-image object. Their striking finding was that the time people needed to decide grew in a straight line with the angle between the two figures. It looked as if people were turning a mental picture at a steady rate, the way you would turn a real object in your hands.
That result helped establish that the mind can work with picture-like representations, not only with words and rules. Holding such a picture for a few seconds without turning it is what the visual memory test checks. Mental rotation tasks are now used widely to study spatial ability. This test uses flat shapes on a grid instead of 3D figures, which works better on a phone screen, but the logic of "same or mirror" is the same.
Strategies that help
- Pick an anchor. Choose one distinctive part of the left shape, such as an arm that sticks out, and find it in the right shape. Then check which side the rest of the shape is on.
- Rotate the smaller way. A turn of 270° is the same as 90° the other way. Turning the shorter distance in your head is faster.
- Check handedness. Like a left and a right glove, a mirror shape looks almost the same but cannot be turned into its partner. If the "arm" ends up on the wrong side after turning, it is Mirror. Left and right differ inside you too: the dominant eye test shows which eye leads when you line things up.
- Practise. Mental rotation improves with practice, and your second and third runs are usually faster.
Limits of an online spatial test
Twenty questions is a short test, so a few lucky or unlucky answers shift your score. A small screen makes the shapes smaller, which can slow you down a little; your results are most comparable on the same device.
Spatial reasoning is only one part of thinking ability, and this test only covers 2D rotation. It is not an IQ test and not a diagnosis of any kind; it is a self-check for curiosity and practice.
More tests of attention, memory and thinking are on the memory and brain tests page.
Source
- Shepard, R. N., & Metzler, J. (1971). Mental rotation of three-dimensional objects. Science, 171(3972), 701–703.
Frequently asked questions
What is a mental rotation test?
You compare two shapes shown at different angles and decide whether one is a rotated copy of the other or a mirror image. To answer, most people turn one shape in their mind until it lines up with the other.
How many questions are there?
20 pairs: 10 where the right shape is the same shape rotated and 10 where it is a rotated mirror image, in random order.
What is a good score?
Guessing gives about 10 out of 20. On this test, 18 or more means you rotated the shapes with very few mistakes. There is no published average for this exact version, so compare your own runs.
Why do larger turns feel harder?
In Shepard and Metzler's 1971 study, the time people needed grew in a straight line with the angle between the figures, as if they were turning a mental image at a steady speed.
Can I improve my spatial reasoning?
Practice on rotation tasks usually makes you faster and more accurate at them. Picking an anchor part of the shape and rotating the shorter way round also helps.
Is this an IQ test?
No. It measures one spatial skill, 2D mental rotation, in a short self-check. It is not an IQ test and not a diagnosis.