How to use the latte factor calculator
- Enter what the small purchase costs each time and how many days per week you buy it.
- Enter the number of years to look ahead and a yearly return for the saved money. Use 0 to see the money alone.
- Read what the habit costs per week, month and year, and what the same money would grow to if you saved it instead.
- Use the table to compare spending and saving year by year.
Formula
Spent per year = cost x days per week x 52
Monthly deposit = spent per year / 12 (end of month)
Saved = deposit x ((1 + i)^n - 1) / i, with i = yearly rate / 12 and n = months
With a 0% return, the saved amount is just the sum of the deposits.
A $5 purchase, 5 days a week
$5 x 5 days x 52 weeks is $1,300 a year, or $108.33 a month. Over 30 years you would spend $39,000.00. If the same $108.33 were saved every month at 6% a year, it would grow to $108,822.46, of which $69,822.46 is growth.
After 1 year the saved total is $1,336.35, after 5 years $7,558.42 and after 10 years $17,753.60.
What the idea is, and what it is not
The latte factor is the idea that small, regular purchases add up to a large sum over time, especially when compared with what the money could grow to. The arithmetic is correct, but it is only part of the picture. Most budgets are decided by big items such as housing and transport, and a small treat you enjoy may be well worth its price.
Use the tool to see the size of a habit, not to judge it. If the number surprises you, decide whether you want to change it. If it does not, you have lost nothing.
About the return
The yearly return is a number you choose, not a prediction. Real returns vary from year to year and can be negative, and fees, taxes and inflation all reduce what you keep. Try 0% for the plain money, then a few cautious rates to see the range. For a closer look at growth, use the compound interest calculator or the savings calculator.
The tool deposits one twelfth of the yearly spend at the end of each month and compounds monthly. To see how a habit compares with your pay, try the cost in work hours calculator.
Assumptions and limits
- A year has 52 weeks, and the spending is the same every week.
- The return is a fixed rate you choose. It is an example, not a forecast.
- Taxes, fees and inflation are not modeled.
- Whole years from 1 to 80 are supported.
Frequently asked questions
What is the latte factor?
It is the idea that a small daily expense, such as a coffee, adds up to a large amount over years, and that investing the same money could grow it further. This tool does the arithmetic so you can see the size of the effect.
How much does a $5 coffee cost per year?
At $5 for five days a week over 52 weeks it is $1,300 a year. Change the price and days to match your own habit.
Is the investment growth guaranteed?
No. The return is a number you type, and real returns can be lower, higher or negative. The tool shows what the math gives for that number, nothing more.
Should I stop buying small things?
That is your decision. The calculator only shows the cost. Many people keep small pleasures and cut elsewhere, and a budget is easier to keep when it has room for them.