Digit Span Test

A digit span test measures how many digits you can hold in working memory and repeat in order. Most adults manage about seven forward and about five backward.

Forward and backward · about 3 minutes

Remember the digits, then type them back

Digits appear one at a time. Type them in the same order for forward span, or in reverse order for backward span. Each round adds a digit. You get two trials per length, and two misses at one length end that part.

Forward starts at 3 digits, then backward starts at 2.

What is a good digit span?

Rough guide based on Miller (1956). Our own bands, not standardised norms.
DirectionTypicalAbove typicalStrong
Forward5 to 8910 or more
Backward4 to 678 or more

Forward, about 5 to 8 digits is typical, centred on the 7 plus or minus 2 that George Miller described in 1956. Backward span is usually about 1 to 2 digits shorter than forward, so about 4 to 6 is typical.

These are rough ranges for adults, not scores from a standardised test. Cowan (2001) argued that the true limit is closer to 4 chunks of information when you cannot rehearse or group items. Digit lists score higher because people rehearse and group digits.

Digit span by age

The general pattern is consistent across the research. Span rises through childhood, peaks in early adulthood and declines slowly later in life.

We do not list age-banded scores here. Reliable age norms come from published test manuals, collected under supervised, standardised conditions. An online task on your own device cannot be compared with them number for number.

Forward vs backward digit span

Digit span is a working memory subtest in the Wechsler scales, such as the WAIS-IV. Joseph Jacobs described the task in 1887. In the Wechsler version, a psychologist reads the digits aloud and records your answers. This page is not a clinical administration.

  • Forward asks you to store digits and repeat them. It leans on short-term storage and attention.
  • Backward asks you to store digits and reorder them. It leans more on working memory and executive control.

Working memory matters for reasoning, reading and mental arithmetic, but it is one of several abilities that make up IQ.

Digit span and attention

Working memory is often discussed in research on ADHD, and clinicians may use digit span as one part of a wider assessment. A low result here does not mean you have ADHD. Tiredness, stress, background noise and a wandering mind all shorten span. Only a qualified clinician can assess attention difficulties.

Frequently asked questions

What is a good digit span?

For digits recalled in order, about 5 to 8 is typical, with 7 the classic average. George Miller summarised this in 1956 as seven, plus or minus two. For digits recalled in reverse, about 4 to 6 is typical. On our rough guide, 9 forward or 7 backward is above typical, and 10 or more forward or 8 or more backward is strong.

Why is backward digit span shorter than forward?

Forward recall mostly needs you to store the digits and repeat them. Backward recall also needs you to reorder them in your head, which uses more working memory. Most people land about 1 to 2 digits lower backward.

What does a digit span test measure?

Forward span mainly reflects short-term storage and attention. Backward span adds mental manipulation, so it leans more on working memory and executive control. It does not measure memory for faces, events or learned facts.

Is digit span part of an IQ test?

Yes. Digit span is a working memory subtest in the Wechsler scales, such as the WAIS-IV. This page is a short online version of the same idea. It is not a clinical administration and its result is not an IQ score.

Can you improve your digit span?

You can get better at the task, mostly by grouping digits into chunks, such as reading 4-8-2-9-1-7 as 482 and 917. Research reviews find that this kind of practice does not reliably carry over to other abilities.

Does a low digit span mean I have ADHD?

No. Working memory difficulties are discussed in ADHD research, but many other things lower span, including tiredness, stress, noise and distraction. A short online test cannot diagnose ADHD or any other condition. If you are worried about attention or memory, speak to a doctor or psychologist.

How does this digit span test work?

Digits appear one at a time. You type them back in order, or in reverse for the backward part. Forward starts at 3 digits and backward at 2. You get two trials at each length. One correct trial moves you up a digit, and two misses at the same length end that part. Your span is the longest length you got right.

Does digit span change with age?

In general, yes. Span rises through childhood, peaks in early adulthood and declines slowly later in life. Exact age-banded scores come from published test manuals used in supervised testing, so we do not give age figures here.

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Sources

  1. Miller, G. A. (1956). The magical number seven, plus or minus two. Psychological Review, 63(2), 81 to 97.
  2. Cowan, N. (2001). The magical number 4 in short-term memory. Behavioral and Brain Sciences, 24(1), 87 to 114.
This is an informal online digit span task, not a clinical test. It cannot diagnose any condition.