How many digits can you hold?

This is the digit span task, one of the oldest tasks in memory research: Joseph Jacobs described it in 1887. In a study of 763 adults, the average was about six and a half digits, and most people scored between five and seven (Woods and colleagues, 2011). George Miller’s famous “seven, plus or minus two” comes from the same family of findings.

Your score shows where you start today, not how far your memory can go. It moves with sleep, stress and attention: take the test on a tired evening and again on a rested morning, and you will see the difference.

Memory athletes recall far longer sequences than the span allows. A study of ten top memory competitors found no differences in the structure of their brains. What set them apart was method: nine of the ten used the memory palace (Maguire and colleagues, 2003).

Two techniques get you started:

• Chunking. Group digits into pairs: 8 5 3 2 1 7 becomes 85, 32, 17. Three items instead of six.
• The number code. Give each digit a letter, turn each pair of digits into a character doing something, and a long number becomes a short story you can see.

Learn chunking · Learn the number code · Try the word test

Twelve words, thirty seconds. Then write down every word you remember, in any order.

There is no pass mark. Note your score, learn the story method or the memory palace, and take the test again with a new list. The only comparison that matters is with yourself.

This test is for training. It does not measure memory health and cannot diagnose anything. If you are worried about your memory, talk to a doctor.