Monthly Payment & Amortization
Updated October 2026
✓ Reviewed by Derek Giordano, BA Business Marketing
Benchmark 30-year fixed mortgage, national average: 7.28% (Oct 1, 2026, Freddie Mac Primary Mortgage Market Survey); 15-year fixed mortgage, national average: 6.60% (Oct 1, 2026, Freddie Mac Primary Mortgage Market Survey).
A mortgage calculator estimates your monthly home loan payment based on the purchase price, down payment, interest rate, and loan term. It also shows total interest paid over the life of the loan — a number that often surprises first-time buyers. On a $400,000 home with 10% down and a 7% rate on a 30-year term, you'll pay roughly $2,395/month in principal and interest, but the total interest over 30 years comes to approximately $502,000 — more than the original loan amount. Understanding this math is essential before signing the largest financial commitment most people ever make.
Enter the home price, your down payment, the annual interest rate, and your preferred loan term. Click Calculate to instantly see your estimated monthly payment, total interest over the life of the loan, and total amount paid. For a more complete picture of what you can afford, factor in property taxes, homeowner’s insurance, and PMI using the optional fields.
Your monthly mortgage payment consists of principal (the loan balance being repaid) and interest. With a 30-year loan at typical rates, early payments are mostly interest — on a $360,000 loan at 7%, your first monthly payment of $2,395 puts only $295 toward principal and $2,100 toward interest. By year 15, the split is roughly even. By year 28, most of each payment goes to principal. This "front-loading" of interest is why extra payments in the early years save far more than extra payments later. The formula used is M = P[r(1+r)ⁿ]/[(1+r)ⁿ−1] where P is the principal, r is the monthly interest rate, and n is the number of payments.
A 15-year mortgage on a $360,000 loan at 6.5% has a monthly payment of $3,137 — about $840 more per month than the 30-year at 7% ($2,395). But the total interest paid drops from $502,000 to $204,000 — a savings of nearly $300,000. The 15-year also typically qualifies for a lower interest rate (often 0.5–0.75% less), making the gap even larger.1
The tradeoff is cash flow flexibility. The higher 15-year payment leaves less room for other investments, emergency savings, or lifestyle spending. Some financial planners argue that taking the 30-year loan and investing the $840/month difference in index funds (historically ~7% after inflation) produces a better long-term outcome than the interest savings — but this assumes disciplined investing, which most people don't maintain. Use our Extra Payment Calculator to see a middle-ground approach: taking a 30-year loan but making extra principal payments when cash flow allows.
This calculator uses a fixed interest rate. With an ARM (adjustable-rate mortgage), your rate can change after an initial fixed period — typically 5, 7, or 10 years. Fixed rates offer predictability; ARMs often start 0.5–1.5% lower but carry risk if rates rise after the adjustment period. ARMs make the most sense when you're confident you'll sell or refinance before the fixed period ends, or when the rate environment suggests rates will fall.2
On a $360,000 loan over 30 years, every 0.25% increase in interest rate adds approximately $57/month and $20,500 in total interest over the life of the loan. The difference between a 6.5% and 7.5% rate is $228/month and $82,000 in total interest. This is why rate shopping matters — getting quotes from 3–5 lenders and negotiating can easily save tens of thousands of dollars. The Consumer Financial Protection Bureau recommends comparing Loan Estimates (the standardized 3-page document every lender must provide) to see the true cost including fees, points, and closing costs.3
20% down eliminates Private Mortgage Insurance (PMI), which typically costs 0.5–1.5% of the loan amount annually. On a $360,000 loan, that's $150–$450/month in PMI on top of your mortgage payment until you reach 20% equity.
10% down is a common middle ground — lower upfront cost but with PMI until you hit 80% loan-to-value. On a $400,000 home, 10% down ($40,000) vs 20% down ($80,000) saves $40,000 upfront but adds roughly $200/month in PMI for 5–8 years.
3–5% down is possible through conventional loans (3% minimum) and FHA loans (3.5% minimum). FHA loans carry an upfront mortgage insurance premium plus annual MIP for the life of the loan. VA loans require 0% down for eligible veterans with no PMI, making them the most favorable option available.
Your actual monthly housing cost is significantly higher than the principal-and-interest number this calculator shows. Budget for property taxes (0.5–2.5% of home value annually, varying wildly by state), homeowner’s insurance ($1,200–$3,000/year for most homes), HOA fees if applicable ($200–$800/month in many developments), and maintenance/repairs (budget 1–2% of home value annually). A $400,000 home with a $2,395 P&I payment may actually cost $3,200–$3,800/month when everything is included. Use our Home Affordability Calculator for the complete picture, or see our Closing Cost Calculator for upfront expenses.
| Loan Amount | 6.0% | 6.5% | 7.0% | 7.5% |
|---|---|---|---|---|
| $200,000 | $1,199 | $1,264 | $1,331 | $1,399 |
| $300,000 | $1,799 | $1,896 | $1,996 | $2,098 |
| $400,000 | $2,398 | $2,528 | $2,661 | $2,798 |
| $500,000 | $2,998 | $3,160 | $3,327 | $3,497 |
→ Run multiple scenarios. Try different inputs to see how changes affect the outcome. Small differences in rates, terms, or amounts can have a large impact over time.
→ Use conservative estimates. When projecting future returns or growth, err on the low side. Optimistic assumptions lead to plans that fall short.
→ Compare before committing. Use the results alongside other financial calculators on this site to see the full picture before making a financial decision.
→ Bookmark for periodic check-ins. Financial situations change — revisit this calculator quarterly or when your circumstances shift to keep your plan on track.
→ Your mortgage payment should stay below 28% of gross income. This is the front-end debt-to-income ratio most lenders use. At $80,000 gross income, that’s a maximum of ~$1,867/month for housing. Use our Home Affordability Calculator for a complete analysis.
→ Compare 15-year vs 30-year side by side. On a $400,000 mortgage at 7%, the 30-year payment is $2,661/month with $558,036 total interest. The 15-year is $3,595/month but only $247,156 total interest — saving $310,880. Our 15 vs 30-Year comparison breaks it down further.
→ Don’t forget the hidden costs of homeownership. Mortgage payment is just the start. Budget 1–2% of home value annually for maintenance, plus property taxes, insurance, HOA fees, and utilities. A $400,000 home typically costs $4,000–8,000/year in maintenance alone.
→ Make one extra payment per year. Adding one extra principal payment per year on a 30-year mortgage can shave 4–5 years off the loan and save tens of thousands in interest. Our Extra Payment Calculator shows the exact impact.
See also: House Hacking Calculator · Mortgage Points Calculator · Home Affordability Calculator · Refinance Break-Even Calculator · Extra Payment Calculator