Save the Difference Calculator

About this calculator

The "save the difference" method is a simple behavioral finance trick: instead of just resolving to spend less, you put a number on a recurring habit's cost and track what skipping it would actually add up to. This calculator multiplies the cost per occurrence by how many times a week you do it, annualizes that to 52 weeks, and then projects the total across however many years you choose.

It's the same arithmetic behind popular personal-finance examples like the "latte factor" — the idea that a daily coffee, a subscription, or any small recurring purchase looks trivial in isolation but compounds into a real sum over years. Budgeters and anyone building a savings goal use this kind of projection to decide whether cutting a specific habit is actually worth the trade-off, and to set a concrete savings target tied to a real behavior change.