What does a daily habit compound to in 5 years?
30 minutes a day, 5 days a week. Linear time = 650 hours. Compounded skill (Atomic Habits 1%/day) = ~270x baseline. The gap is the entire point.
How the math works
Two parallel calculations, both projected month-by-month over your time horizon.
- Linear time: practice days × daily minutes. This is the obvious "I spent X hours" line.
- Compounded skill:
skill = baseline × (1 + dailyImprovement)practice days × (1 − dailyDecay)off dayswith dailyDecay derived from annual decay rate ÷ 365. - Baseline (no-practice control): same starting point, only decay applies. The widening gap between the two curves is the visible value of consistency.
Why 1% daily improvement? James Clear's Atomic Habits framing: small daily improvements compound. 1.01365 ≈ 37.78. The point isn't the specific number — it's the contrast between linear time invested and exponential skill compounded.
Milestones (21 days = habit forming, 66 days = habit automatic) come from Phillippa Lally's 2009 European Journal of Social Psychology study.
Math runs locally. Inputs never leave your browser. Skill compounding is a model, not a measurement of any specific skill.
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