Habit Streak Calculator

Work out habit streak instantly with clear inputs, formula shown and shareable results.

About Habit Streak Calculator

From 1 June to 4 September 2026 is 96 days, so three missed days leave 93 completed at 96.9% adherence and seven days short of a hundred. Adherence rate is the more useful measure than an unbroken streak, because it survives a missed day without resetting motivation to zero.

Formulas

Days completed

completed = days since start - days missed

Adherence rate

rate = completed / total days x 100

Worked example

With the default values below, Habit Streak Calculator returns Days Completed of 93. Change any input above and every figure here is recalculated in your browser.

Inputs used

Streak start: 2026-06-01
Today's date: 2026-09-04
Days missedminimum 0: 3

Results

Days Completed: 93 days
Days Since Starting: 96
Adherence Rate: 96.9%
Days To Reach 100: 7

Step by step

1Values used
2Days completed
3Adherence rate
4Days Completed= 93 days
5Days Since Starting= 96
6Adherence Rate= 96.9
7Days To Reach 100= 7

Assumptions and limits

The result is derived only from the 3 inputs listed above. Anything not among them is not part of the calculation.
In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
Figures are rounded for display to 1 decimal place, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.

How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.

Frequently Asked Questions

Does one missed day break a habit?

No. Research on habit formation finds a single lapse has little effect; it is the abandonment after a lapse that does the damage.

How long does a habit take to form?

Median around 66 days in Lally's study, but the range ran from 18 to over 250 depending on the behaviour's complexity.