Guides
Original explainers next to the calculators. They describe the arithmetic and the limits — not a product pitch.
Written by the Finance Calculator Pro team. Educational only; not financial advice. Primary sources are linked where a rule or definition is invoked. Start with amortization if you want the payment formula, or jump to refinance and affordability if you already have a note or a budget.
Featured · 4 min read
How mortgage amortization works
Why a fixed payment starts as mostly interest and ends as mostly principal — and how extra payments change the schedule.
15-year vs 30-year mortgages
Payment, total interest, and the rate-and-term trade-off, without invented average spreads.
4 min read
When refinancing makes sense
Break-even, reset terms, cash versus rolled-in costs, and what a calculator cannot see.
3 min read
How much house you can afford
The 28/36 illustration versus ability-to-repay, taxes, insurance, and cash to close.
3 min read