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Digit Span Test

How many digits can you hold in mind at once? This is the working memory subtest used in the Wechsler IQ scales, run at the same one digit per second, and scored against published adult norms so you get a percentile rather than just a number.

Type the digits in the order you saw them.

Digits appear one at a time, one per second.

Starts at 3 digits and adds one each time you get it right. It ends on your first mistake.

Or take the full 50-question IQ test

This measures one domain. A full IQ score needs four.

Verbal, numerical and spatial reasoning are the other three. Our 50-question assessment covers all of them and gives you a score with your exact percentile.

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What digit span measures

Digit span is one of the oldest measures in psychology, and it has survived because it is simple and it works. Your span is the longest sequence you can reliably hold and reproduce, and it is remarkably stable: most adults land between 5 and 9 digits forward, clustering just under 7.

The forward and backward versions are not the same test. Repeating a sequence forwards is mostly storage: you hold it and read it back. Repeating it backwards makes you hold the sequence and operate on it at the same time, which is what working memory actually refers to. That is why backward span runs one to two digits shorter, and why it correlates more strongly with general cognitive ability.

Both are part of the Working Memory Index on the Wechsler Adult Intelligence Scale, alongside arithmetic and letter-number sequencing.

The chunking problem

Anyone can beat their own span with a trick. Group the digits into pairs, or map them onto years, phone numbers or ages, and you are no longer holding nine separate items, you are holding three or four compressed ones. This is why the world record for digit span runs into the hundreds and tells you nothing about the person's memory.

The sequences here avoid immediate repeats and simple runs to make casual chunking harder, but no browser test can stop a determined strategy. If you want a number that means something, do not try. And it is the reason that training your digit span does not make you smarter: you are learning an encoding trick for this specific task, not expanding the underlying capacity.

Frequently asked questions

What is a normal digit span?

For healthy adults, forward digit span averages just under 7 digits, and most people fall between 5 and 9. Backward span runs one to two digits shorter, averaging around 5. Span declines gradually with age and is reduced by fatigue, stress and distraction, so a single result on a given day is not a fixed trait.

What is the difference between forward and backward digit span?

Forward span is mostly a measure of short-term storage: you hold the sequence and repeat it. Backward span requires you to hold the sequence and manipulate it at the same time, which is what working memory actually means. Backward span is the harder task and correlates more strongly with general cognitive ability.

Is digit span the same as IQ?

No. Digit span measures working memory, which is one of several cognitive domains that contribute to a full-scale IQ score. Someone can have an excellent digit span and unremarkable verbal or spatial reasoning, or the reverse. It is one component, not a substitute.

Why do the digits appear one per second?

That rate is part of the standardised task. Presenting digits faster turns it into a test of reading speed, and presenting them slower gives people time to rehearse and encode, which inflates the span. The one-per-second rate is what the published adult norms were collected with.

Can you improve your digit span?

You can improve your score on this specific task with practice, largely by learning chunking strategies such as grouping digits into pairs or mapping them onto dates. That improvement tends not to transfer to other working memory tasks or to general ability, which is the same pattern found in the wider research on brain training.

How accurate is this compared with a clinical test?

This runs one trial at each length and stops on your first mistake. A clinical administration such as the WAIS-IV gives two trials at every length and only discontinues after both fail, which is a more reliable estimate of your true maximum span. Treat this as an indication rather than an assessment.

Working memory is one domain of four

A digit span tells you how much you can hold in mind. It says nothing about your verbal, numerical or spatial reasoning. Our 50-question assessment measures all four and gives you a full-scale score with your exact percentile.

Take the full test

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Related

Sources

  • Wechsler, D. (2008). WAIS-IV Technical and Interpretive Manual. Pearson. (Digit Span administration, the two-trial discontinue rule, and adult norms.)
  • Miller, G. A. (1956). The magical number seven, plus or minus two. Psychological Review, 63(2), 81-97.
  • Woods, D. L., et al. (2011). Improving digit span assessment of short-term verbal memory. Journal of Clinical and Experimental Neuropsychology, 33(1), 101-111.