A ₩4,500 daily habit adds up to ₩90 million by 85, or over ₩300 million invested
₩4,500 a day does not feel like much. It is a pack of cigarettes or a can of beer on the way home. But daily spending grows as the days add up.
How to calculate a habit’s lifetime cost
There are two steps.
- Lifetime spend = daily spend × 365.25 × remaining years
- Invested value = the same amount set aside every month, compounded monthly at an annual return
The first is money actually spent. The second shows what it could have become if saved instead.
₩4,500 versus ₩15,000 a day
Assume age 30 to 85, 55 years, and a 4% annual return.
| Daily spend | Per year | 55-year total | Invested at 4% |
|---|---|---|---|
| ₩4,500 | about ₩1.64M | about ₩90.4M | about ₩328.4M |
| ₩15,000 | about ₩5.48M | about ₩301.3M | about ₩1,094.7M |
₩4,500 a day becomes about ₩90 million over 55 years. Set aside monthly and grown at 4%, it passes ₩300 million. The invested figure is 3.6 times the spend, because compounding grows with time.
What to keep in mind
The invested figure assumes a steady 4% every year for 55 years. Real returns rise and fall, and inflation erodes what the same amount buys. So the ratio between the two totals is more useful than the ₩300 million itself.
Future price increases for cigarettes or alcohol are not included. If prices rise, the spend total will be higher than the table. Health costs are not counted either.
To convert the cost into working time instead of money, see A new phone costs 13 workdays on a ₩2.5M monthly salary.
Frequently asked questions
What happens if I set the return to 0?
You see the money simply set aside, with no investing. The invested value equals the lifetime spend.
How do I enter a habit that is not daily?
Divide your weekly or monthly spend into a daily average. Two ₩30,000 nights a week is about ₩8,600 a day.
What end age should I use?
The default is 85. You can also enter the age you expect to stop. Try assuming you quit in ten years and compare.
To run your own numbers, use the Habit cost calculator.