How the habit cost calculator works
It is one multiplication. The price each time, times the times a week, times 52 weeks. $5.50 five times a week is $27.50 a week and $1,430 a year. Ten years is $14,300, with no interest added and no price rises, so the figure is a floor rather than a forecast.
If the habit also takes time, add the minutes. Ten minutes for that coffee, five days a week, is about 43 hours a year. Some habits are expensive in money and cheap in time, like an energy drink. Others cost nothing and eat an evening, like scrolling. Both numbers belong in the decision.