See what a daily coffee or any small recurring habit costs per month and year, and what it would grow to if invested instead.
Latte Factor Formula
The calculator converts a repeated small purchase into a monthly cost, then projects what that money would become if invested:
M = C * W * 52 / 12
FV = M * ((1 + r/12)^(12n) - 1) / (r/12)
Variables:
- M is the habit’s cost per month
- C is the cost per purchase and W is purchases per week (7 for daily, 5 for weekdays, or a custom count)
- r is the expected annual investment return as a decimal (the calculator defaults to 7%)
- n is the number of years, and FV is the future value if the money were invested monthly instead of spent
Enter the cost per purchase and how often you buy, then set the years and expected return (both default sensibly if left blank). The calculator returns the weekly, monthly, and annual habit cost, the total spent over the period, the value if invested instead, and the compound growth on top of the spending – the “latte factor” itself.
Common Habits Invested for 10 Years at 7%
What familiar small purchases become when redirected into investments for a decade.
| Habit | Monthly cost | Spent over 10 yrs | Invested value |
|---|---|---|---|
| $5.50 latte, weekdays | $119 | $14,300 | $20,600 |
| $12 lunch out, weekdays | $260 | $31,200 | $45,000 |
| $18 delivery, 2x per week | $156 | $18,720 | $27,000 |
| $8 pack-a-day equivalent | $243 | $29,200 | $42,100 |
| $4 energy drink, daily | $121 | $14,560 | $21,000 |
Example Problems
Example 1: The classic weekday latte.
A $5.50 latte on weekdays: W = 5, so M = 5.50 x 5 x 52 / 12 = $119.17 per month. Over 10 years that is $14,300 spent. Invested monthly at 7%: FV = 119.17 x ((1.005833^120 – 1) / 0.005833) = about $20,600.
Example 2: A twice-a-week delivery habit.
$18 per order, twice a week: M = 18 x 2 x 52 / 12 = $156 per month. Over 5 years at 7%, FV = about $11,170, versus $9,360 simply spent.
Frequently Asked Questions
What is the latte factor?
A term popularized by author David Bach for the long-term cost of small recurring purchases. The insight is not about coffee specifically – it is that any few-dollar habit, multiplied by hundreds of repetitions and compound growth, quietly represents five-figure money over a decade.
Does this mean I should never buy coffee?
No. The point is awareness, not deprivation: keep the habits that genuinely add to your life and consciously redirect the ones that do not. Cutting one neutral habit and automating the freed-up cash into an index fund captures the entire benefit without touching what you love.
Why use a 7% return?
It approximates the long-run inflation-adjusted return of a broad U.S. stock index fund. The default is editable – use a lower rate to be conservative or to model a savings account, or a higher one for a nominal (before-inflation) projection. The comparison’s shape holds at any reasonable rate.
