Mortgages & Financing

A mortgage is a loan secured by real property — meaning if you stop making payments, the lender can foreclose and take ownership of the home. That security is what allows lenders to offer long repayment terms at relatively low interest rates compared to unsecured debt like credit cards. Understanding this basic structure helps clarify every other decision you will make about financing, and it also explains why mortgages carry protections and requirements that other consumer loans do not.

Every monthly mortgage payment is split between principal (repaying the amount you borrowed) and interest (the cost of borrowing that money). Additionally, most homeowners pay property taxes and homeowners insurance monthly into an escrow account managed by the lender, so their full monthly payment is often referred to as PITI: principal, interest, taxes, and insurance. Depending on your down payment and loan program, you may also pay mortgage insurance monthly. On a typical PITI payment, principal and interest usually make up the largest share, with taxes and insurance combined running 20 to 30 percent of the total. Understanding this composition matters because when you see quoted monthly payments in listings or calculators, they may or may not include the full PITI. Always calculate your true monthly cost with taxes and insurance included.

In the early years of a mortgage, the vast majority of your payment goes to interest. This is a consequence of how amortization works: interest is calculated each month based on the outstanding principal balance, so when the balance is high (early in the loan), the interest portion is large. As you pay down principal, the interest calculation each month is against a smaller balance, so more of your payment goes to principal. This creates a curve where principal paydown accelerates over time. On a $350,000 loan at 7 percent, your first payment is roughly $2,330 — about $2,042 goes to interest and only $288 reduces your principal. By year 15, that split has shifted significantly, with roughly $1,200 going to interest and $1,130 to principal. By year 25, the majority of each payment reduces principal. This front-loading of interest is why extra principal payments early in a mortgage are disproportionately powerful — an extra $200 monthly in year one saves far more interest over the life of the loan than the same $200 in year 20.

Amortization schedules are worth studying explicitly for any mortgage you take on. Every mortgage calculator can generate one. Look at the schedule for your specific loan and understand how much you will owe at various milestones — after 5 years, 10 years, 15 years. This makes concrete what would otherwise be abstract. It also lets you model prepayment scenarios: what happens if you pay an extra $100 monthly, what if you make one extra payment per year, what if you round every payment up to the nearest $500. Even modest prepayments compound into significant interest savings and reduced payoff timelines.

Lenders profit from mortgages in multiple ways. They earn origination fees at closing (typically 0.5 to 1.5 percent of the loan amount). They earn interest on the loan over time, which is why they prefer that you keep the loan as long as possible. They may sell the loan to investors on the secondary market — Fannie Mae, Freddie Mac, private investors — earning a servicing fee to continue processing your payments even after they no longer own the loan itself. Sometimes the loan is sold immediately after closing to another servicer entirely, which explains why some buyers get notices about their loan being transferred within weeks of closing. This is normal and does not change the terms of your loan; only who you send payments to.

The relationship between purchase price, loan amount, and monthly payment is often confused. The purchase price is what you agree to pay for the home. The loan amount is what you borrow, which is the purchase price minus your down payment (and sometimes minus other credits). The monthly payment is determined by the loan amount, interest rate, and loan term through the amortization calculation. On a $400,000 purchase price with 20 percent down ($80,000), the loan amount is $320,000. At 6.5 percent on a 30-year term, the principal and interest payment is roughly $2,022 per month. Adding taxes, insurance, and any PMI or HOA fees gives the true monthly cost. The buyer who quotes their "mortgage" as $2,022 is understating what they actually pay every month.

The rate you are offered on a mortgage is not fixed — it is a function of your credit profile, the loan structure, the loan-to-value ratio, the loan program, market conditions on the day of your lock, and how aggressively you shop. Two lenders quoting the same nominal rate can differ materially in fees, discount points, and other terms that affect your true cost. This is why comparing Loan Estimates side by side is essential; the headline rate alone is not enough information to compare offers.

Understanding the mortgage's total cost matters for lifetime financial planning. On a $320,000 loan at 6.5 percent for 30 years, you pay $2,022 per month for 360 months, totaling $727,920. Of that, $320,000 is the original loan and $407,920 is interest. You pay more in interest over the life of the loan than the original loan amount. This is not necessarily a bad deal — inflation, the utility of housing over 30 years, and appreciation of the underlying asset all improve the overall picture — but it is important to see the number and understand what a long-term mortgage actually costs in total dollars.

The mortgage is a tool. Used well, it lets you own an appreciating asset while deploying capital gradually rather than all at once. Used carelessly, it becomes a burden that limits your other financial options for decades. The rest of this course walks through how to structure, shop, and manage your mortgage so that it works in your favor rather than against you