What this calculator does
It adds up what a regular expense costs over time: a daily coffee, a streaming service, cigarettes, lunch out or a gym membership. You get the total for the years you choose, plus a table for 1, 5, 10, 20 and 30 years. You can let the price rise each year, and you can see what the same money would have grown to if it had been invested at a return you choose. It doesn't judge the habit. Some habits are worth their cost to you, and the numbers are just there to help you decide.
How it's calculated
Cost in year y = yearly cost × (1 + price increase)y − 1
Total = sum of the yearly costs
For the invested-instead figure, each year's cost is split into 12 equal monthly amounts, each added at the end of its month, and the balance grows at the monthly rate that compounds to your yearly return:
Balance = balance × (1 + monthly rate) + this month's spending
This is the same compound-growth idea used in the SEC's Investor.gov calculator.
Worked example
$5 a day is 5 × 365 = $1,825 a year. With no price increase, 10 years cost $18,250.
If the price rises 3% a year, year 2 costs $1,879.75, year 3 costs $1,936.14, and so on. The 10-year total is 1,825 × (1.03¹⁰ − 1) ÷ 0.03 = $20,921.58.
If, instead, that $1,825 a year (with no price increase) went into an account earning 7% a year, it would grow to about $26,014 after 10 years. The extra $7,764 is growth, not money you spent.
What the numbers don't tell you
- Returns aren't guaranteed. The invested figure assumes a steady return every year. Real investments rise and fall, can lose money, and may have fees and taxes. Try a few different rates.
- Price increases are your guess. Some costs rise faster than general inflation and some don't rise at all. The inflation calculator shows how US prices have changed in the past, using the BLS Consumer Price Index.
- Results are in future dollars. A total 30 years out isn't adjusted back to today's buying power.
- Cutting back has costs too. A cheaper swap (coffee made at home, say) still costs something, so subtract that to see the real saving.
These figures are for planning and comparison. They aren't advice about what to spend or invest.