Calculate your exact monthly mortgage payment and understand the full cost of your home loan. Enter your loan amount, interest rate, and term to instantly see your payment breakdown, total interest, and total amount paid over the life of the loan.
A mortgage calculator uses the standard loan amortization formula to determine your fixed monthly payment. The formula is M = P[r(1+r)^n] / [(1+r)^n - 1], where P is the principal loan amount, r is the monthly interest rate (your annual rate divided by 12), and n is the total number of monthly payments (years multiplied by 12). This formula ensures that each monthly payment covers both the accruing interest and a portion of the principal, so the loan reaches exactly zero at the end of the term.
Understanding how amortization works helps you make smarter decisions. In the early years of a mortgage, the majority of each payment goes toward interest rather than principal. For example, on a $300,000 loan at 6.5% over 30 years, your first payment of $1,896 sends about $1,625 to interest and only $271 to principal. By year 20, that same $1,896 payment applies roughly $900 to principal. This gradual shift is why extra payments made early in the loan have such a dramatic effect on the total interest paid.
Loan amount: $300,000 | Interest rate: 6.5% | Term: 30 years. Monthly P&I payment = $1,896.20. Total paid over 30 years = $682,632. Total interest = $382,632 — more than the original loan amount.
Same $300,000 at 6.5% over 15 years. Monthly payment = $2,613.32. Total interest paid = $170,397 — saving over $212,000 compared to the 30-year option. The tradeoff is $717 more per month.
$400,000 loan for 30 years at 6.0% vs 7.0%: At 6%, monthly payment = $2,398 and total interest = $463,353. At 7%, monthly payment = $2,661 and total interest = $558,036. That one percentage point difference costs $94,683 more over the life of the loan.
The Monthly P&I (Principal and Interest) is your base mortgage payment before taxes or insurance. The Total Monthly figure adds property tax and insurance when you enter those optional fields — this is your true housing cost, sometimes called PITI. The Total Interest Paid shows the full cost of borrowing, which often surprises first-time buyers. The Total Amount Paid is the sum of all 360 (or 180) payments combined.
The most valuable use of this tool is scenario comparison. Try entering your loan amount at the rate your primary lender quoted, then reduce it by 0.25% and 0.5% to see how much you'd save by shopping around. Even a 0.25% rate reduction on a $350,000 mortgage saves approximately $18,000 in total interest. Similarly, compare a 30-year vs 15-year term to decide whether the higher monthly payment is worth the massive interest savings. Finally, try increasing your loan amount by $20,000 or $30,000 to model what a larger home purchase would actually cost monthly — this prevents overextending your budget.
This calculator covers principal and interest only. For a complete picture of homeownership costs, you should also budget for Private Mortgage Insurance (PMI) if your down payment is under 20% — typically 0.5–1.5% of the loan amount annually. HOA fees in many communities run $200–$600/month. Maintenance costs typically average 1% of the home's value per year. Closing costs at purchase usually run 2–5% of the purchase price and are paid upfront.
What counts as a good rate depends on the current market environment, your credit score, down payment, and loan type. Generally, rates within 0.5% of the national average for your loan type and term are considered competitive. Check current published averages from Freddie Mac's weekly survey as a benchmark.
Conventional loans typically require 3–20% down. Putting 20% or more eliminates the requirement for PMI and results in a lower monthly payment. FHA loans allow as little as 3.5% down for qualifying borrowers. VA and USDA loans may allow 0% down for eligible applicants.
A 15-year mortgage costs significantly less in total interest but has a higher monthly payment. Choose 15 years if you can comfortably afford the higher payment and want to build equity faster. Choose 30 years if you need the lower payment flexibility, or plan to invest the difference. Run both scenarios in this calculator to see your specific numbers.
Extra payments go entirely to reducing your principal balance, which reduces future interest charges. Even one extra payment per year on a 30-year loan can cut 4–6 years off the loan and save tens of thousands in interest. The earlier in the loan you make extra payments, the greater the impact.
No. If your down payment is under 20%, add approximately 0.5–1.5% of your loan amount annually (divided by 12) to your monthly payment estimate to account for PMI. PMI is typically removed once you reach 20% equity in the home.