A mortgage is a loan secured by the home you buy. If you stop paying, the lender can foreclose and sell the property to recover its money. Understanding the moving parts before you apply helps you compare offers and avoid surprises.
Principal, interest, taxes and insurance
Your payment has up to four pieces, often called PITI. Principal repays the amount borrowed. Interest is the lender's charge for lending it. Property taxes and homeowners insurance are usually collected monthly into an escrow account and paid on your behalf. Some loans also add private mortgage insurance and HOA dues.
Amortization: why early payments are mostly interest
Most US mortgages are fully amortizing: the payment stays the same, but the split changes every month. Interest is calculated on the remaining balance, which is highest in year one, so the earliest payments are mostly interest. Over time the balance falls and more of each payment reduces principal. An amortization schedule makes this visible and shows how much total interest you will pay over the life of the loan.
Key terms to know
The loan-to-value ratio compares the loan to the home's value. The annual percentage rate folds in certain fees so you can compare offers. Points are upfront fees that buy a lower rate. A rate lock freezes your quoted rate for a set number of days while your loan closes.
Try the numbers
Use our Mortgage Payment Calculator to see this in practice. With its default example (Home price: $400,000; Down payment: 20%; Interest rate: 6.5%), it shows total monthly payment: $2,539. Adjust the inputs to match your situation.
Key takeaways
- A mortgage payment has principal, interest, taxes and insurance, and sometimes PMI and HOA dues.
- Early payments are mostly interest because interest accrues on the largest balance.
- Compare APR, not just the interest rate, when shopping lenders.
This article is for general education and is not personalized financial, tax or legal advice. Rules and limits change; confirm current figures with official sources such as IRS.gov, SSA.gov and StudentAid.gov, or consult a qualified professional. © 2026 FinanzCalc.