Buying a home is likely the biggest financial decision of your life. Understanding exactly how your mortgage payment is calculated — and what happens to your money over decades — can save you tens of thousands of dollars.
A mortgage is a loan specifically for buying property. The property itself serves as collateral — if you stop paying, the lender can take the property. Most mortgages run 15 to 30 years, making them the longest financial commitment most people ever make.
P = Loan amount, r = Monthly rate, n = Total payments
Loan amount: $240,000
Monthly payment: $1,597
Total paid over 30 years: $574,920
Total interest paid: $334,920 — more than the original loan!
| Factor | Impact |
|---|---|
| Loan amount | Higher loan = higher payment |
| Interest rate | Even 0.5% difference = thousands over 30 years |
| Loan term | 30yr has lower monthly but far more total interest vs 15yr |
| Down payment | Larger down payment = smaller loan = lower monthly |
| Credit score | Better score = lower interest rate offered |
This is one of the most important decisions in home buying:
If you can afford the higher monthly payment, a 15-year mortgage almost always makes better financial sense over the long term.
Amortisation is the process of paying off your loan through regular payments. Early in the loan, most of your payment goes to interest. Over time, more goes to principal. This is why paying extra early saves so much — it reduces the principal that interest is calculated on.
It depends on how long you plan to stay. Generally, buying makes financial sense if you'll stay 5+ years in the same location. For shorter periods, renting is often cheaper when you factor in transaction costs, maintenance, and opportunity cost.
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