The Blog
Practical writing on compound interest, debt, and long-term planning. Each post includes worked examples and links to the relevant calculator.
The Rule of 72: How to Estimate Compound Growth in Your Head
A 300-year-old approximation that lets you mentally compute how long it takes money to double at any rate. Surprisingly accurate up to about 20%.
Read post →Simple vs. Compound Interest: The Gap That Builds (or Drains) Wealth
The difference looks tiny at first and then becomes enormous. A side-by-side walk-through with worked numbers and where each type shows up in real products.
Read post →What's coming
We're working on more posts: how to retire by 50 starting at 30, why a 1% mortgage rate cut is worth more than you think, the math of dollar-cost averaging in volatile markets, and a deep dive on real (inflation-adjusted) returns. Tell us what to write next.