How these numbers are calculated

The steps

1. 1Each task produces a raw score (milliseconds for reaction time, correct answers for the rest).
2. 2The raw score is converted to a standard score (z) using that task’s mean and standard deviation. Reaction time is inverted, because lower is better.
3. 3The z score is mapped onto the standard normal distribution to give a percentile.
4. 4The age figure starts at 38 and moves 9 years per standard deviation, clamped to 18–80.
5. 5The overall brain age uses the mean z across the tasks you completed. You do not need to finish all six.

Distribution parameters in use

These are provisional, informed by commonly reported age trends in experimental psychology. They will be updated once we have real measurement data, and this page will be updated with them.

Reading the numbers

• This is entertainment, not a medical test. It cannot diagnose anything or assess your health.
• The same person can move by tens of milliseconds depending on sleep, time of day, and how quickly their device responds. Reaction time in particular depends heavily on your screen and input method.
• Because the parameters are provisional, the percentile is a rough guide. Comparing against your own previous run, under the same conditions, tells you more than comparing against other people.
• Everything runs in your browser. Scores are never sent to a server.