A mortgage is a loan used to buy property, where the property itself is used as collateral. Understanding its basic parts makes it much easier to compare offers later.
The four main parts
- Principal — the amount you actually borrow, after your down payment.
- Interest rate — the yearly cost of borrowing, expressed as a percentage. Fixed-rate mortgages keep this the same for the whole term; adjustable-rate mortgages can change it over time.
- Term — how many years you have to repay the loan, commonly 15 or 30 years. A shorter term means higher monthly payments but usually far less total interest.
- Down payment — the amount you pay upfront. A larger down payment lowers your principal (and often your interest rate), which lowers both your monthly payment and total interest.
Why term length changes the total cost so much
Because interest is charged on the remaining balance, stretching the same loan amount over more years means more total interest paid, even at the same rate. A 30-year loan and a 15-year loan on the same amount can differ by tens of thousands of dollars in total interest, even though the 15-year option has a higher monthly payment.
What a lender is actually evaluating
Lenders typically look at your income stability, existing debt relative to income, and credit history to decide both whether to approve you and what rate to offer. A stronger financial picture generally leads to a lower rate, which compounds into meaningfully lower total interest over a long loan term.
Try the numbers yourself
Our Mortgage & Loan Payment Calculator lets you compare how changing the term or down payment shifts your monthly payment and total interest — useful before comparing real offers from lenders.