Why Use a Mortgage Calculator?
Buying a home is one of the most significant financial decisions you’ll ever make. Understanding how your monthly mortgage payment breaks down can help you budget effectively and explore different scenarios—whether you’re choosing between a 15‑year vs. 30‑year term or deciding how much down payment to put down. Mortguage.app gives you instant estimates for your monthly payment, total cost, and total interest, so you can plan with confidence.
How the Calculation Works
At its core, your mortgage payment is determined by three factors:
- Loan Amount: The total principal you’re borrowing (e.g. $300,000).
- Interest Rate: Your annual percentage rate (APR), divided by 12.
- Term Length: The number of years you’ll take to pay off the loan.
We use the standard amortization formula:
M = P·r ÷ (1 – (1 + r)–n)
,
where P=principal, r=monthly rate, n=total payments.