10,000-hour calculator

Enter how much you practice and see the day you reach your goal.

How long 10,000 hours takes

Starting from nothing, with no days off unless the row says so.

What the research says

The number comes from a 1993 study of violin students by the psychologist K. Anders Ericsson and his colleagues. By age 20, the violinists had averaged about 10,000 hours of deliberate practice, and even they weren't yet masters. Malcolm Gladwell's 2008 book Outliers turned that average into the "10,000-hour rule".

Ericsson himself said the rule was wrong in several ways (Peak, 2016). The hours it takes vary from one field to another, and what counts is deliberate practice: focused work on what you can't yet do, with feedback, rather than time spent going through the motions.

Practice still matters a lot, though not equally everywhere. A 2014 analysis of 88 studies in Psychological Science found that practice explained about 26% of the differences in skill in games, 21% in music, 18% in sports, 4% in education, and under 1% in professions (Princeton University).

So 10,000 hours isn't a finish line or a guarantee. It's a sense of scale: real skill takes years of steady work, and how you practice matters as much as how long. Counting the hours keeps both in view.

Count yours as you go

Lifetimer keeps a running total of every hour you put into a skill, from a stopwatch, a timer, or time you add afterward, and forecasts the date you'll reach your next milestone from your real pace over the last 30 days. See how to track practice hours for a simple way to set it up.

Coming to iPhone and Android in November.