How does a 15-year vs 30-year mortgage compare?

A 15-year mortgage has higher monthly payments but you pay significantly less total interest — often 40–60% less. A 30-year mortgage has lower monthly payments, giving you more cash flow flexibility.

What is an amortization schedule?

An amortization schedule shows each monthly payment broken down into principal and interest. Early payments are mostly interest; later payments shift toward principal as the balance decreases.

Does this calculator include PMI?

Private Mortgage Insurance (PMI) is not included in this calculator. PMI typically applies when your down payment is less than 20% and costs 0.5%–1.5% of the loan amount annually.

Mortgage Calculator

Calculate your monthly mortgage payment, total interest paid, and amortization breakdown for any home loan.

Home Price ($)

Down Payment ($)

Annual Interest Rate (%)

Loan Term (years)

Your Mortgage Estimate

Monthly Payment (P&I) —

Loan Amount —

Total Interest Paid —

Total Cost (P + I) —

Payoff Date —

How to Use the Mortgage Calculator

A mortgage calculator lets you estimate your monthly payment before you ever talk to a lender. Enter your home price, down payment, interest rate, and loan term to get your principal-and-interest payment instantly. This mortgage calculator uses the standard amortization formula used by every bank and mortgage company in the United States.

Understanding Your Inputs

Home Price: The purchase price of the property. If you're still browsing, use your target budget. If you have a specific home in mind, use the listing price or agreed sale price.

Down Payment: The upfront amount you pay out of pocket. The standard recommendation is 20% to avoid Private Mortgage Insurance (PMI). On a $400,000 home, 20% is $80,000. A higher down payment reduces your loan amount and monthly payment.

Interest Rate: The annual rate your lender charges. Your actual rate depends on your credit score, debt-to-income ratio, and current market conditions. As of 2025, average 30-year fixed rates are in the 6.5%–7.5% range. Use Freddie Mac's Primary Mortgage Market Survey for the latest weekly averages.

Loan Term: Most mortgages are 30 years or 15 years. A 30-year loan has lower monthly payments; a 15-year loan saves significantly on total interest.

The Mortgage Payment Formula

Monthly mortgage payments are calculated using the standard amortization formula:

M = P × [r(1+r)ⁿ] / [(1+r)ⁿ − 1]

Where: M = monthly payment, P = principal loan amount, r = monthly interest rate (annual rate ÷ 12), n = total number of payments (loan term in years × 12).

For a $320,000 loan at 6.75% for 30 years: r = 0.0675/12 = 0.005625, n = 360 payments. Monthly payment = $2,076.

What Your Mortgage Payment Doesn't Include

The monthly payment calculated here covers principal and interest (P&I) only. Your actual monthly housing cost will also include:

Property taxes: Typically 1%–2% of home value annually, divided into monthly escrow payments
Homeowner's insurance: Average $150–$200/month nationally
PMI (if down payment < 20%): 0.5%–1.5% of loan amount annually
HOA fees: If applicable — can range from $100 to $1,000+/month

When budgeting, add 25%–40% to your P&I payment to estimate total monthly housing costs.

30-Year vs. 15-Year Mortgage: Which Is Better?

On a $320,000 loan at comparable rates, the difference is dramatic. A 30-year mortgage at 6.75% produces a $2,076/month payment and $427,000 in total interest. A 15-year mortgage at 6.25% produces a $2,745/month payment but only $174,000 in total interest — a savings of over $250,000.

Choose a 15-year mortgage if you can comfortably afford the higher payment and want to minimize lifetime borrowing cost. Choose a 30-year mortgage if cash flow flexibility is your priority — you can always make extra principal payments to pay it down faster.

Mortgage Calculator — Frequently Asked Questions

A standard mortgage payment (PITI) includes Principal, Interest, Taxes, and Insurance. This calculator computes the principal and interest portion. Property taxes and homeowner's insurance are added by your lender to an escrow account and paid out separately. PMI applies if your down payment is less than 20%.

Use the annual interest rate quoted by your lender. As of 2025, 30-year fixed rates range from 6.5%–7.5% for borrowers with good credit. For a quick estimate, check Freddie Mac's Primary Mortgage Market Survey for the latest weekly averages, or get pre-approved with 2–3 lenders to compare rates.

A 15-year mortgage has higher monthly payments but you pay significantly less total interest — often 40–60% less over the life of the loan. A 30-year mortgage has lower monthly payments, giving you more cash flow flexibility each month. Most financial advisors suggest choosing the 30-year if the 15-year payment would stretch your budget.

An amortization schedule shows every monthly payment broken down into principal and interest portions. In the early years, most of your payment goes to interest. Over time, as the balance decreases, a larger portion goes toward principal. By year 20 of a 30-year loan, most of each payment is principal.

No. Private Mortgage Insurance (PMI) is not included in this calculation. PMI is required by most lenders when your down payment is less than 20% of the purchase price. It typically costs 0.5%–1.5% of the original loan amount per year, or roughly $100–$300/month on a $300,000 loan.