Everyday money decisions
The small, repeated choices — a daily habit, a single purchase — and what they quietly add up to over a lifetime.
- Opportunity cost: what a purchase really costs you (not just the price) The price tag isn't the real cost of a big purchase. See what that money would be worth if you invested it instead of spending it — the opportunity cost, the growth you quietly give up. Open →
- The cost of a habit: what a small, daily spend adds up to A few dollars, often enough, becomes real money. See what a recurring habit costs over the years — and what the same money could have grown to if you'd invested it instead. Open →
- The latte factor: what a small daily spend really adds up to David Bach's latte factor says your daily coffee is costing you a million dollars. The honest math is smaller — but still surprising. Run it here with your own numbers. Open →
- Sunk cost: when to quit "I've spent too much to stop now" is the most expensive way to decide. Money already spent is gone on both paths — the honest math compares only what comes next, and this calculator does it for you. Open →
- Repair or replace? The repair quote on one side, the new-model price on the other: the honest comparison isn't between the two prices but between their costs per year of service. Two costs, two lifespans, a verdict — and proof that the "50% rule" sometimes gets it wrong. Open →