Free tool · Memory
Digit span memory test
Most adults can repeat back about 6 to 7 digits in order. In a 2011 study of 763 adults aged 18 to 65, the average was about 6.4 digits forward and 4.6 backward. Take the test to see your own span.
Digit span test
- Digits appear one at a time, about one a second.
- When they stop, type them back with the keypad or your keyboard.
- Lists start at 3 digits and grow by one. You get two lists at each length.
- The test ends when you miss both lists at one length.
Type the digits in the order you saw them: 3 8 5 is 385.
The digits don't wait, because timing is part of what the test measures. Start when you're ready and somewhere quiet.
Runs in your browser. Nothing you type or answer is sent anywhere.
How to take the test
- Choose “Forward (same order)” or “Backward (reverse order)”.
- If you like, switch on “Read the digits aloud” (shown when your device has a speech voice) and “Remember my last result on this device”.
- Select “Start the test”. After “Get ready”, digits appear one at a time, each on screen for about 0.8 seconds with a short blank before the next.
- When they stop, type the digits with the on-screen keypad or your keyboard, then select “Check my answer”. “Delete” and “Clear” fix slips; pasting is blocked.
- Lists start at 3 digits. You get two lists at each length, and the test ends when you miss both.
The digits don’t wait for you, because the timing is part of what’s being measured. Screen readers announce each digit as it appears. With “Read the digits aloud” on, your device speaks them instead and the announcements stay quiet, so you don’t hear each digit twice. If you switch tabs while digits are showing, that list doesn’t count and you get a new one of the same length.
How the score is worked out
Your span is the longest list you recalled correctly. After both lists at a length, you move up one digit if you got either of them right, and the test stops when you miss both. Each digit is a random number from 1 to 9, and the same digit never appears twice in a row.
The result also shows a mean span, the scoring used by Woods and colleagues. It starts at the first list length minus 0.5, then adds the share of lists you got right at each length from there upward. That works out to roughly the length you’d get right half the time, and it uses every answer rather than only the best one.
Say you get both lists of 3, 4 and 5 digits right, one of the two lists of 6, and neither list of 7. Your span is 6. Your mean span is 2.5 + 1 + 1 + 1 + 0.5 + 0 = 6.0. Against the 763 adults in Woods’s study (average 6.35, standard deviation 1.15), a span of 6 is within the typical range, which runs from about 5.2 to 7.5.
Average digit span
The comparison figures come from Woods and colleagues (2011), who tested two groups with a computerized version of the task.
| Group | Forward span | Backward span |
|---|---|---|
| 763 community adults, aged 18 to 65 (average age 46.5) | 6.35 (SD 1.15) | 4.61 (SD 1.22) |
| 30 adults, aged 18 to 46 | 7.36 (SD 0.88) | 5.80 (SD 1.42) |
On their mean-span scoring, the larger group averaged 6.52 forward and 4.91 backward. In that group, forward span wasn’t linked to age, while backward span was slightly lower in older participants (a small but significant correlation).
Those numbers sit close to a famous older one. In 1956 George Miller observed that the span of immediate memory “is about seven items in length”, and that recoding items into chunks is “an extremely powerful weapon” for holding more. Later work by Nelson Cowan (2001) suggests the core limit is closer to about four chunks when rehearsing and grouping are prevented. Digit span tests give larger numbers because people do group and rehearse the digits.
Forward and backward
Backward span is lower on average: by 1.74 digits in the 763-adult group. Repeating digits in order mostly asks you to hold them. Reversing them asks you to hold them and rearrange them at the same time, so the backward test leans harder on what psychologists call working memory.
Practice and strategy
A little, on this task. In Woods’s first experiment, people tested on three days improved by about 0.30 digits forward and 0.45 digits backward on the mean-span measure. That’s why the tool notes that a second score isn’t a clean comparison with the first.
Strategy moves the number too. Psychologists describe two kinds of chunking: a deliberate kind, like splitting a phone number into groups, and an automatic kind that builds up with experience (Gobet and colleagues, 2001). Miller called recoding into chunks a powerful way to hold more, and grouping digits in twos or threes as they appear is a simple version of it. A better score on this test shows you got better at this test.
How this version differs from the lab
Woods’s participants heard the digits through headphones at one a second, on a computerized test with its own rules for making the lists longer and shorter. This version shows the digits on a screen (or reads them with your device’s voice) and uses two lists at each length. It also runs on whatever device and in whatever room you’re in. So the comparison with the study averages is a rough one.
What the result doesn’t tell you
A digit span isn’t an IQ score, and it can’t diagnose ADHD, dementia or any other condition. One run can be thrown off by tiredness, noise or a lapse in attention. If you’re worried about memory or attention, a doctor or a qualified psychologist can use standardized assessments. For an everyday look at how memory fades after learning, try the forgetting curve calculator.
Digit span memory test: common questions
What is a normal digit span?
Most adults repeat back about 6 to 7 digits forward and about 4.5 to 6 backward. In Woods and colleagues' 2011 study of 763 adults aged 18 to 65, the average was 6.35 digits forward and 4.61 backward. A smaller group of 30 adults aged 18 to 46 averaged 7.36 forward and 5.80 backward.
What is a good digit span?
There's no pass mark. In the 763-adult study, spans from about 5.2 to 7.5 digits forward, and about 3.4 to 5.8 backward, were within one standard deviation of the average. A single try at home that lands outside that range says little on its own, because noise, tiredness and practice all move the score.
What does the digit span test measure?
It measures how many items you can hold in mind for a few seconds and repeat back in order, a short-term memory task. The backward version adds the work of rearranging the digits as you recall them. It's one narrow measure, and this tool doesn't turn it into an IQ score.
How do you test short-term memory online?
A digit span test is one of the simplest ways. Digits appear one at a time, you type them back, and the lists get longer until you miss twice at one length. Take it in one sitting, somewhere quiet, on a device you're used to, and treat the result as a rough guide.
Can a digit span test detect ADHD?
No. A digit span from a web test can't diagnose ADHD, dementia or any other condition. If you're worried about your attention or memory, talk to a doctor or a qualified psychologist, who can use standardized assessments and look at the whole picture.
Related tools
- Forgetting curve calculatorHow fast memory fades after learning, and what each review changes.
- Attention span testA four-minute focus check: press for every number except 3, and see where you slip.
- Reading speed testYour words per minute on a real passage, with a comprehension check.
Guides
- How to remember what you readRecall a chapter before you reread it, write one sentence from memory and review it days later. What the reading research supports, and why highlighting rates low.
- How to improve attention span, according to the researchThe popular 8-second figure has no research behind it. What Gloria Mark's 47 seconds measures, what short-video studies found, and changes worth testing.