Guides
Understand the math behind the numbers
Short, practical explainers on the reasoning behind each calculator — no jargon, worked examples where it helps.
How Mortgage Amortization Actually Works
Most of an early mortgage payment goes to interest, not principal. Here is the math behind why, and when that flips.
What Cap Rate Really Tells You (and What It Hides)
A high cap rate is not automatically a good deal. Here is what the number includes, and the three things it leaves out.
Renting vs Buying: Finding Your Real Breakeven Point
The right answer to "rent or buy" depends on one number most people never calculate: their breakeven year.