What is a Mortgage
A mortgage is a loan used to purchase real estate, where the property itself serves as collateral — repaid through regular monthly payments over 15 to 30 years, covering both principal and interest.
A mortgage is a type of secured loan used to finance the purchase of real estate — typically a home. The property itself serves as collateral, meaning the lender can foreclose and take ownership if the borrower stops making payments. Mortgages are typically repaid over 15 or 30 years through monthly payments that cover both principal (loan balance reduction) and interest, along with property taxes and homeowner's insurance if held in escrow.
For most households, a mortgage is the single largest financial commitment they will ever make — and understanding how one works is essential to making a sound decision.
Key Mortgage Components
- Principal: The original amount borrowed
- Interest rate / APR: The cost of borrowing, expressed annually
- Term: Length of the loan — typically 15 or 30 years
- Down payment: The portion of the purchase price paid upfront (not financed)
- Monthly payment: The fixed amount paid each month (for fixed-rate mortgages)
- Escrow: Many lenders collect property taxes and homeowner's insurance as part of the monthly payment, held in escrow and paid on the borrower's behalf
Fixed-Rate vs. Adjustable-Rate Mortgages (ARM)
| Type | Rate | Best For |
|---|---|---|
| Fixed-rate | Stays the same for the life of the loan | Buyers who value predictability and plan to stay long-term |
| Adjustable-rate (ARM) | Fixed for initial period, then adjusts periodically | Buyers planning to sell or refinance before rate adjusts |
A 5/1 ARM, for example, has a fixed rate for the first 5 years, then adjusts annually based on a benchmark index. ARMs can offer lower initial rates but introduce uncertainty.
15-Year vs. 30-Year Mortgage
| 15-Year | 30-Year | |
|---|---|---|
| Monthly payment | Higher | Lower |
| Total interest paid | Much lower | Much higher |
| Equity building | Faster | Slower |
| Best for | Those who can afford higher payments and want to minimize interest | Those who need lower payments or plan to invest the difference |
On a $300,000 loan at 7%, a 30-year mortgage costs ~$418,000 in interest; a 15-year costs ~$186,000. The 15-year saves ~$232,000 in interest — but at a significantly higher monthly payment.
What Lenders Evaluate (Mortgage Qualification)
Lenders assess:
- Credit score — Generally, 620+ for conventional loans; 580+ for FHA loans
- Debt-to-income ratio — Typically must be below 43%
- Down payment — Conventional loans typically require 5–20%; FHA loans allow 3.5%
- Employment and income history — Generally 2 years of stable employment preferred
- Assets and reserves — Lenders want to see you have funds beyond the down payment
Mortgage Amortization
Mortgage payments are structured through amortization — early payments are mostly interest; later payments are mostly principal. In the early years of a 30-year mortgage, you build equity very slowly despite making regular payments. This is why extra principal payments early in the loan have such an outsized impact on total interest paid and payoff timeline.
Private Mortgage Insurance (PMI)
If your down payment is less than 20% on a conventional loan, lenders typically require PMI — private mortgage insurance — which protects the lender (not you) if you default. PMI typically costs 0.5%–1.5% of the loan amount annually, added to your monthly payment. Once your equity reaches 20%, you can request PMI removal.
Comparing Mortgage Rates
Even a small rate difference has a major impact over a 30-year term. Shopping with multiple lenders before committing is strongly recommended. Bankrate publishes current mortgage rates from multiple lenders and allows side-by-side comparisons.
Mortgage and Net Worth
Your home equity — the market value of your home minus your remaining mortgage balance — is typically the largest component of net worth for American homeowners. As you pay down your mortgage and home values appreciate, equity grows, increasing your net worth.