Financial Guides & Calculator Tips
5 of 14 posts
15-Year vs 30-Year Mortgage: A Real-Numbers Comparison
The 15 vs 30 year mortgage choice is really a trade between monthly cashflow and lifetime interest. A worked example shows the size of that trade and how to think about it.
How Is a Mortgage Payment Calculated? Formula + Example
The mortgage payment formula in plain English, with a step-by-step worked example on a 300,000 loan at 5% over 25 years — showing exactly how the monthly payment and total interest are built.
The Rule of 72: When the Mental Shortcut Actually Breaks
The rule of 72 is the back-of-envelope trick for compound growth. Here is how it works, where it stays accurate, and the cases where it quietly misleads.
Compound vs Simple Interest: The Difference in Real Numbers
A plain English guide to compound vs simple interest, with both formulas, a worked example using 10,000 at 7 percent over 20 years, and a free calculator to test your own numbers.
Investing 500 a Month for 30 Years: Realistic Projections
What does 500 a month invested for 30 years actually become? A plain English walkthrough of the math, the assumptions, and what the numbers depend on.