Calculate your monthly mortgage payment, total interest paid, and payoff date. Compare 15 vs 30-year loans and see how extra payments save you thousands.
Buying a home is the largest financial decision most people will ever make, and understanding your mortgage payment is the critical first step. A mortgage calculator allows you to estimate your monthly principal and interest payment before you even set foot in a bank, giving you the confidence to shop for homes within your true budget.
This calculator uses the standard amortization formula used by banks and lenders worldwide. Enter your home price, down payment, annual interest rate, and loan term to instantly compute your fixed monthly payment, the total interest you will pay over the life of the loan, and a year-by-year breakdown showing how each payment is split between principal and interest.
Understanding these numbers helps you compare offers from multiple lenders, decide between a 15-year and a 30-year term, and see the dramatic impact that even a small rate difference — say 6.0% vs 6.5% — has on your lifetime cost. Most borrowers are surprised to learn that on a 30-year loan, they often pay more in interest than the original amount borrowed.
Before you start house-hunting, you need to know what you can actually afford. Pre-qualification letters from lenders tell you the maximum you could borrow, but that ceiling is rarely what you should borrow. This calculator lets you run "what-if" scenarios in seconds: What if I put 20% down instead of 10%? What if I choose a 15-year term? What if I make one extra payment per year?
Real estate agents, loan officers, and financial advisors all recommend running these numbers before making an offer. It protects you from overextending your budget and helps you negotiate from a position of knowledge.
M = P × [r(1+r)^n] / [(1+r)^n − 1] Where: M = fixed monthly payment P = principal loan amount (home price − down payment) r = monthly interest rate (annual rate ÷ 12 ÷ 100) n = total number of monthly payments (years × 12)
Result: $2,023.65/month
A $400,000 home with 20% down ($80,000) leaves a $320,000 loan. At 6.5% over 30 years, the monthly P&I payment is $2,023.65. Total interest over the life of the loan is $408,514, bringing total cost to $728,514. Adding $200/month extra would save ~$78,000 in interest and pay off the loan 5 years early.
When you make a mortgage payment, it is split between interest and principal. In the early years, most of each payment goes to interest. On a $320,000 loan at 6.5%, your first monthly payment of $2,023.65 includes $1,733 in interest and only $291 toward principal. By year 15 the split is roughly even, and in the final years almost all of each payment reduces principal.
A fixed-rate mortgage locks in your interest rate for the entire term — your payment never changes. An adjustable-rate mortgage (ARM) starts with a lower rate for an introductory period (commonly 5 or 7 years) then adjusts annually. ARMs can save money if you sell or refinance before the adjustment, but carry the risk of rising rates.
Borrowers often focus on the monthly payment, but total cost matters more. A $320,000 loan at 6.5% for 30 years costs $728,514 total — more than double the loan. A 15-year term at 5.8% brings total cost to $479,760 — saving nearly $249,000.
A mortgage is a secured loan used to purchase real estate. The property itself serves as collateral — if you stop making payments, the lender can foreclose. Most mortgages are fully amortizing, meaning each payment covers both interest and a portion of the principal until the loan is paid off.
The interest rate has a huge impact. On a $300,000, 30-year loan, the difference between 6.0% and 7.0% is about $200/month and over $72,000 in total interest. Even a quarter-point difference changes the monthly payment by roughly $50 and total interest by $18,000.
A 15-year mortgage has higher monthly payments (roughly 40–50% more) but a lower interest rate and far less total interest — often less than half. Choose 15 years if you can comfortably afford it; choose 30 years for flexibility with the option to pay extra.
This calculator shows principal and interest (P&I). Your actual payment usually also includes property taxes and homeowners insurance (often escrowed), and possibly PMI — collectively called PITI.
The 28/36 rule says spend no more than 28% of gross monthly income on housing costs and no more than 36% on total debt. A household earning $8,000/month should keep total housing under $2,240.
Private Mortgage Insurance is required when your down payment is less than 20%. It costs 0.5%–1% of the loan per year. Lenders must automatically cancel PMI when your balance hits 78% of the original home value.
Extra payments go directly toward reducing principal. Since interest is calculated on the remaining balance, reducing it faster means less interest accrues. Even $100/month extra can save tens of thousands of dollars and years off a 30-year mortgage.
It uses the exact amortization formula banks use, so P&I is accurate. It does not include property taxes, insurance, PMI, or HOA, which vary by location.