The Universal Calculation Engine
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The Universal Calculation Engine

Mortgage Basics

The biggest payment in many households—worth reading slowly.

Start this lessonTotal interest 15 vs 30 years

What “PITI” captures

Principal and interest are the loan mechanics. Taxes and insurance are often escrowed—same monthly check, different recipients. Your all-in housing cost matters for budgeting.

Fixed vs ARM

Fixed-rate loans lock the rate for the term. ARMs trade lower initial rates for future uncertainty—read adjustment caps, indexes, and margins before you celebrate the teaser.

Use the calculator

FAQ

What’s PMI?

Private mortgage insurance protects the lender when equity is thin. It can fall off at LTV thresholds—rules vary by loan type and servicer.