Housing & mortgages

Principal and interest usually dominate the payment, but property taxes, homeowners insurance, PMI, and HOA fees can add hundreds of dollars. A calculator separates P&I from those other lines so you can see what moves if the rate changes versus if the tax bill changes.

A lower rate on the same loan amount reduces interest over time, but the payment drop may be smaller than you expect because most early payments are interest anyway. Compare scenarios with the same down payment and term so you are not mixing variables.

Fixed-rate loans keep the same note rate for the life of the loan (until you refinance or pay off). Adjustable-rate mortgages (ARMs) start with a fixed period, then reset based on an index plus a margin spelled out in your note.

ARMs can make sense when you know you will sell or refinance before the first reset, but the reset cap and worst-case payment matter. Model the reset path with conservative assumptions rather than the teaser rate alone.

Refinancing replaces your old loan with a new one. Closing costs and any prepaid items are paid again (or rolled in). Break-even is how many months of lower payments it takes to recover those costs—not whether you “save interest” over 30 years on paper.

If you extend the term when you refinance, the payment may fall even when the rate is similar. Compare total interest and payoff date, not just the monthly check.

Renting avoids maintenance surprises and keeps down payment cash liquid. Buying builds equity only after transaction costs and early-year interest. A fair comparison includes rent growth, maintenance, property tax changes, and how long you stay.

There is no universal winner. Run both sides with the same time horizon and conservative appreciation; treat appreciation as uncertain, not guaranteed.