Cost of a Habit Calculator
Turn a small recurring spend into its yearly cost, its cost over years, and what it could grow to invested.
How it works
yearly = cost × times/week × 52 · over N years = yearly × N · invested = yearly × ((1+r)ᴺ − 1) ÷ r
The yearly cost is the price each time times how often, across 52 weeks. Over your chosen span that simply multiplies out. The invested figure treats each year’s spending as one contribution to an account earning your assumed return, compounding for the remaining years — the standard future-value-of-an-annuity formula. It’s a nudge about opportunity cost, not a verdict: a habit you genuinely value can be money well spent.
Worked example
$6 five times a week is $30 a week — $1,560 a year. Over 10 years that’s $15,600 spent. Invested at 7% as each year’s money frees up, the stream compounds to about $21,554 — roughly $5,950 of it pure growth.
Frequently asked questions
Why use 7% for the investment return?
US stocks have returned around 10% a year long-term, about 7% after inflation, so 7% approximates growth in today’s buying power. It’s a rough benchmark — any given decade can land well above or below it, so treat the invested figure as illustrative.
Do I have to quit the habit entirely?
No — that’s the point of showing the yearly cost. Cutting the frequency in half saves half the money while keeping half the enjoyment. The math is meant to make an invisible recurring spend visible, not to shame any particular purchase.
How do I enter a monthly or daily habit?
For a daily habit, set times per week to 7. For a monthly one, either use the cost each time with times per week of about 0.23 (12 ÷ 52), or simply divide the monthly cost by 4.33 and enter that weekly.
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The invested-value figure is an illustration using an assumed return, not a prediction. Actual investment returns vary and can be negative.