Time and money
How money grows when you leave it alone, and how a few years of patience turn small, steady sums into large ones.
- Compound interest: how small, steady money turns into a lot See what a starting sum plus a regular contribution grows to over time — and how much of the final number is money you put in versus growth the years did for you, year by year. Open →
- Financial independence (FIRE): your number and how far away it is Financial independence is the point where your investments can cover your spending without a paycheck. See your FIRE number — and, given what you save and earn, how many years away it is. Open →
- The cost of waiting: what 'I'll start investing next year' really costs Putting off investing feels free — no bill ever arrives. But the delay has a precise price: the growth your early contributions never get to do. Calculate it with your numbers. Open →
- The rule of 72: how long your money takes to double Divide 72 by the rate and you get the doubling time — finance's most durable piece of mental math. Compare it with the exact answer, then read it backwards: how fast inflation halves your cash. Open →