How Many Digits Can You Remember?

weirdly accurate.

How Many Digits Can You Remember?

How many digits can you remember?

Most adults can hold about six. On a digit span test, where you repeat a list of digits back, the 763 adults aged 18 to 65 in Woods and colleagues’ 2011 study averaged 6.35 digits in order and 4.61 backwards, and 80% of forward spans fell between 5 and 7. That is close to George Miller’s famous “seven, plus or minus two” from 1956, but a little lower.

This test runs the classic forward and backward digit span task on a split-flap board. Digits flip up one at a time, two a second, and when the list is done you type it back on a keypad. Lists are random, with no digit twice and no easy runs like 4-5 or 2-4. You start at three digits and each right list adds one; a miss gives you a fresh list at the same length, and a second miss ends that half. Then the same again backwards, last digit first. Your span is the longest list you got right, placed on a bell curve fitted to the 763 adults’ mean and spread.

It is not an IQ test and not a memory check-up. Digit span is one subtest inside clinical batteries such as the Wechsler scales, but one subtest is not an IQ score, and this version is not standardised against them. It also differs from the study: those adults heard the digits one a second and said them back, with two lists at every length; here you see them twice as fast and tap them, and two misses anywhere end a half. So the percentile is an estimate, and tiredness moves it too: in the same paper a person’s span changed by about one digit from one day to the next.

What the test measures

One thing: how long a list of digits you can hold for a few seconds, forward and then backwards.

The task

  • Forward and backward digit span, the two halves of the classic task: repeat the list in the order shown, then last to first
  • Random lists of the digits 0–9 flipping up one at a time on a split-flap board, two a second, using Woods et al.’s (2011) rules for which digits may sit next to each other
  • Start at 3 digits, one more after every right list, up to 14 forward and 12 backward
  • Two misses per half: the first brings a fresh list at the same length, the second ends that half

Your result

  • Your forward and backward span in digits, and roughly what share of 763 adults aged 18–65 (Woods et al. 2011) you beat on each
  • The gap between forward and backward, next to the study’s average gap of 1.7 digits
  • Every list on a ladder, and a replay of the lists you missed with the kind of slip each was
  • Reference points: younger volunteers in the same paper (7.4 forward, 5.8 backward), Miller’s seven plus or minus two, Cowan’s four chunks, and a student who trained his span to 79
  • Which everyday numbers fit in your span in one go, and which only fit in chunks: a 6-digit code, a 10-digit phone number, a 16-digit card number
  • A shareable card and a link that challenges a friend; the link carries your two spans inside the link itself

Before you start

  • About two minutes, free, no sign-up
  • Works on a phone or a computer; on a computer the number keys, Backspace and Enter work too
  • Sound is optional: the digits are shown, not spoken

Digit span FAQ

Is this test free? Do I need to sign up to see my result?

Yes, it’s free, and there’s nothing to sign up for: no account, no email, no payment. Your result appears on this page the moment you finish, and you can share it or play again straight away.

What is a good digit span?

A forward span of 7 or more is above average for adults. In Woods et al.’s 2011 sample of 763 adults aged 18 to 65, the average forward digit span was 6.35, the median was 6, and 80% scored between 5 and 7. Backward spans averaged 4.61, with 74% between 4 and 6. In the same paper, 30 younger volunteers with a mean age of 26 averaged 7.4 forward and 5.8 backward.

Does a digit span test measure IQ?

No. Digit span is one subtest inside clinical batteries such as the Wechsler intelligence and memory scales, but a single subtest is not an IQ score, and this online digit span test is not standardised against those scales. It measures one thing: how long a list of digits you can hold for a few seconds. It says nothing about reasoning, knowledge or intelligence.

Is “seven, plus or minus two” true?

Roughly, for digits, but seven is not the real limit. George Miller’s 1956 paper noted that people can repeat about seven digits, close to the 5–7 range most adults reached in Woods et al.’s 2011 data. Nelson Cowan’s 2001 review found that when people are stopped from grouping items into chunks, short-term memory holds about four chunks; digit lists stretch further because people group and rehearse them.

Why is backward digit span harder than forward?

Backward digit span asks you to hold the list and reverse it at the same time, so it takes more than storage. In Woods et al.’s 2011 sample of 763 adults, backward span was 1.7 digits shorter than forward on average, and it was backward span, not forward, that dipped slightly with age.

How accurate is an online digit span test?

This one gives an estimate, good to about a digit. The 763 adults in the comparison study heard digits one per second and said them back, with two lists at each length; this test shows digits twice as fast, you tap them, and two misses anywhere end a half, so a run can read a digit lower. In the same paper, one person’s span changed by about one digit from one day to the next.

Can you improve your digit span?

Yes, with a strategy, by a lot. In Ericsson, Chase and Faloon’s 1980 study, a student known as SF practised for more than 230 hours, recoding digits as running times, and raised his digit span from 7 to 79. What grew was his chunking, the same reason phone numbers are printed in groups, not the raw number of things he could hold.

Is a low digit span a sign of memory problems?

Not on its own. A short span on one try is usually tiredness, distraction or an awkward list, and this test is a game, not a medical or cognitive assessment. Clinicians judge memory with longer, standardised tests. If you are worried about your memory, talk to a doctor.

Where the numbers come from

Percentiles compare your spans with Experiment 2 of Woods et al. (2011): 763 adults aged 18–65 from a community sample in Rotorua, New Zealand. The paper reports means and SDs, not every score, so the shares come from a bell curve fitted to them, which matches the proportions the paper gives to within about three points. Those adults heard the digits and said them back; here you see and tap them, so the comparison is an estimate. The site does not publish its own players’ data.

How the score works

Two-miss ladder

One list per length. A right list moves you up one digit; the first miss repeats the length with a new list, and the second miss, at any length, ends that half. Missing both lists at 3 digits scores 2.

Percentile

A normal curve with the study’s mean and SD (forward 6.35 ± 1.15, backward 4.61 ± 1.22), cut into whole digits. Your percentile counts everyone with a shorter span plus half of those tied, kept between 1 and 99.