Free Mortgage Calculator
Estimate your monthly payment including taxes, insurance, and PMI with a full amortization schedule.
Year-by-Year Amortization Schedule
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A mortgage calculator is a free online tool that estimates your monthly home loan payment using the standard amortization formula. Enter your home price, down payment, interest rate, and loan term to instantly compute your principal and interest payment, then add property taxes, homeowners insurance, and PMI for a complete picture of your total monthly housing cost. The calculator also generates a year-by-year amortization schedule so you can see exactly how much of each payment goes toward principal versus interest over the life of the loan.
What makes this tool different: Standard mortgage calculators skip the details. CalcInstant includes PITI (principal, interest, taxes, insurance), PMI on the correct loan amount, a full yearly amortization table, biweekly payment savings, closing costs, rent-versus-buy comparison, and an interactive chart — all updated in real time without a single click.
How the mortgage calculator works
The calculator uses the standard mortgage formula: M = P × [r(1+r)^n] ÷ [(1+r)^n − 1], where P is your loan principal (home price minus down payment), r is your monthly interest rate (annual rate divided by 12), and n is the total number of monthly payments (loan term in years times 12). The result is the fixed monthly payment that will fully amortize your loan over the chosen term. To this base payment, the calculator adds one-twelfth of your annual property taxes and homeowners insurance (escrow costs), plus the monthly PMI cost calculated from your home price and PMI rate. The total is your true monthly housing expense — what you would actually pay to a lender each month.
For example, a $350,000 home with a 20% down payment ($70,000), a 6.5% interest rate, and a 30-year term results in a principal and interest payment of approximately $1,770 per month. Adding $3,000/year in taxes ($250/month), $1,200/year in insurance ($100/month), and 0.5% PMI ($146/month) brings the total monthly payment to about $2,266. The amortization schedule then shows how over the first year, roughly $1,890 of each monthly payment goes to interest while only about $270 reduces the principal — a crucial insight for anyone considering a mortgage.
The calculator also handles down payment as either a dollar amount or a percentage, and automatically syncs the two fields so you can experiment freely. Your loan term can be any number of years, with convenient preset buttons for 15 and 30 years. All inputs are saved locally in your browser, so if you are comparing multiple properties over several days, your numbers will still be there when you return.
When to use a mortgage payment calculator
Use this mortgage calculator when you are shopping for a home and want to understand how much house you can afford. Adjust the home price and down payment to see how different scenarios affect your monthly payment. Compare a 15-year versus 30-year loan term side by side to decide which fits your budget and long-term financial goals. The amortization schedule is especially useful when planning extra principal payments — you can see exactly how much interest an extra $100 per month would save over the life of the loan. Realtors, mortgage brokers, and financial advisors also use mortgage calculators to help clients understand the true cost of homeownership beyond just the purchase price.
The chart in this calculator plots your loan balance over time, making it easy to visualize how equity builds as the years progress. On a standard 30-year mortgage, the balance decreases slowly at first — after 10 years, you will still owe roughly 80% of the original principal. By year 20, the curve steepens as more of each payment goes toward principal. This visual representation helps homeowners understand why making extra payments early in the loan term has an outsized impact on total interest savings and payoff speed.
First-time home buyers should use this calculator early in their house-hunting process to establish a realistic budget before visiting open houses. By adjusting the home price and down payment, you can determine the maximum purchase price that keeps your monthly payment within a comfortable range. The calculator's inclusion of property taxes, insurance, and PMI ensures that your budget accounts for the full cost of homeownership — not just the principal and interest that banks typically quote. This comprehensive view prevents the common mistake of underestimating monthly housing costs and stretching too thin financially.
Understanding PMI and down payments
Private Mortgage Insurance is one of the most misunderstood costs in home buying. PMI protects the lender, not the buyer, and is required when your down payment is less than 20% of the purchase price. PMI typically costs between 0.3% and 1.5% of the original loan amount per year, depending on your credit score and loan-to-value ratio. For a $350,000 home with a 10% down payment ($35,000), PMI would add roughly $100 to $150 to your monthly payment. The good news is that PMI is not permanent — once your equity reaches 22%, lenders are legally required to cancel it. Using this mortgage calculator with PMI enabled gives you the most accurate picture of your early homeownership costs, and you can see exactly when you would cross the 20% equity threshold by reviewing the amortization schedule.
Frequently asked questions
What is the monthly payment on a $300,000 mortgage at 7% interest?
A $300,000 mortgage at 7% over 30 years has a monthly principal and interest payment of $1,995.91. Total interest over the life of the loan: $418,527. Over 15 years at the same rate, the payment rises to $2,696.48 but total interest drops to $185,366 — saving $233,161 by choosing the shorter term. Enter your amount and rate above for your exact payment.
How much house can I afford on a $80,000 salary?
The standard guideline is to spend no more than 28% of gross monthly income on housing costs (PITI: principal, interest, taxes, insurance). On $80,000/year ($6,667/month), that's $1,867/month maximum. At 7% interest over 30 years, $1,867/month supports roughly a $280,000 mortgage. Add your down payment to find the maximum purchase price.
What is the difference between a 15-year and 30-year mortgage?
A 30-year mortgage has lower monthly payments but much higher total interest. A 15-year mortgage typically has a lower interest rate (often 0.5–0.75% less) and you pay off the loan twice as fast. On a $250,000 mortgage: 30-year at 7% costs $348,772 in total interest; 15-year at 6.5% costs $138,048 — a $210,724 difference. Monthly payment is $677 higher for the 15-year.
How much do I need for a down payment on a house?
Conventional loans require 3–20% down. FHA loans require 3.5% minimum (or 10% with a credit score below 580). VA and USDA loans require 0% down for eligible borrowers. Putting less than 20% down on a conventional loan requires PMI (private mortgage insurance), typically 0.5–1.5% of the loan annually. The 20% threshold eliminates PMI and reduces your monthly payment.
What is PMI and how do I avoid paying it?
PMI (Private Mortgage Insurance) protects the lender if you default and is required when your down payment is below 20%. It typically costs 0.5–1.5% of the loan amount annually ($100–$250/month on a $200,000 loan). Avoid it by putting 20% down, using a piggyback loan (80-10-10), or requesting cancellation once your equity reaches 20% (required by law at 22% equity).
How do extra mortgage payments reduce interest and payoff time?
Extra principal payments dramatically reduce total interest and payoff time. On a $300,000 mortgage at 7% over 30 years, paying an extra $200/month saves $57,000 in interest and cuts 4 years off the loan. Paying one extra full payment per year saves $45,000 and cuts 4.5 years. Apply extra payments directly to principal — confirm with your lender that they're applied correctly.