1% better every day calculator

Getting 1% better each day means multiplying by 1.01, again and again. After a year that is 1.01 to the power of 365, which is about 37.78. Going 1% worse is 0.99 to the power of 365, about 0.026, or less than 3% of where you began. The calculator does the same sum for any rate and any number of days.

The idea was made popular by James Clear in Atomic Habits, and before that by Dave Brailsford's approach to British Cycling, which he called the aggregation of marginal gains: many small improvements that add up to a large one.

Nothing improves by a fixed percentage every day. Early progress at a new skill is fast, later progress is slow, and a habit is either done or not done on a given day. So 37.8 is not a prediction for your running or your Spanish. It is a way of seeing that small, repeated gains are worth more than they feel like on any one day.

The more useful lesson is in the shape. At 1% a day you are only 1.35 times better after a month, and 2.7 times after 100 days. Half of the final number arrives in the last ten weeks of the year. Most people quit at the flat part, which is exactly why the steep part is rare.

All of these are the same formula with a different rate or length.

The percentage cannot be measured, but showing up can. The practical version of the 1% idea is a small habit done on most days: ten minutes of practice, a page of notes, one more rep. In BeHabitual a timer habit counts the minutes, and the month grid shows whether the days are actually adding up or only the intention is.