How to improve your short-term memory

Short-term memory is what you use to hold a phone number while you dial it, or remember where a card was in a matching game. It's small and it fades fast: most people can keep about seven digits in mind, and without repeating them they're mostly gone within half a minute.

You can't make it dramatically bigger, but you can learn to use it much better. This guide explains how it works and the techniques that make the most difference, with tests to try each one.

Short-term memory and working memory

Short-term memory holds information for a few seconds. Working memory is short-term memory in use: holding things in mind while you do something with them, like adding numbers in your head or following directions. The two terms are often used interchangeably, and the tests on this site measure both.

Its capacity is limited. A well-known 1956 paper by the psychologist George Miller described it as "seven, plus or minus two" items. Later research suggests the real limit is closer to four meaningful chunks, and that people reach seven or more by grouping things together.

Chunking: the biggest trick

Chunking means grouping single items into bigger units. The digits 1 9 8 4 2 0 2 6 are eight items, but "1984" and "2026" are just two years. Phone numbers are written in groups for exactly this reason.

On the number memory test, try reading the number in pairs or threes ("47, 81, 93") instead of digit by digit. Most people gain one to three digits straight away. On the sequence memory test, notice shapes the pattern makes, such as a line or a corner, instead of remembering every square separately.

Say it, picture it, link it

Rehearse: repeat what you need to remember silently. It keeps it fresh for longer.
Use more than one sense: say the number to yourself while picturing it, or name the pictures in a memory game out loud.
Link new things to things you know: 314 as the start of pi, 007 as James Bond.
Use places: picture each item in a room you know well. This, the method of loci, is how memory champions remember long lists.

Look after the basics

Sleep matters more than any technique. Memory is noticeably worse after a short night, and sleep is when the brain turns the day's memories into lasting ones. Regular exercise, staying hydrated and taking breaks from long stretches of focus all help too.

Distraction is the enemy of short-term memory. A notification arriving while you're holding a number in mind is often enough to lose it, which is why these tests work best in a quiet moment with full screen on.

Does memory training work?

Practice on a memory test reliably makes you better at that test, often a lot better. Whether that carries over to everyday life is less clear: research has found that training one task tends to improve that task and close relatives of it, rather than memory in general.

So the techniques are the valuable part. Chunking, linking and rehearsing work just as well for shopping lists, names and revision as they do for the tests here. Use the tests to practise them and to see your progress.