Mortgage Calculator
Calculate monthly mortgage payments with taxes, insurance, and PMI. Enter loan amount, interest rate, and term. Free with amortization schedule.
Mortgage Calculator - Monthly Payment Estimator
Calculate your monthly mortgage payment including principal, interest, taxes, insurance, and PMI. See total cost and amortization breakdown for your home loan.
Last updated: January 2026Reviewed by NovaCalculator Finance Editorial Team
Calculator
Adjust values & calculateAmortization Summary
Formula
Where M = Monthly payment (principal & interest), P = Loan principal (home price minus down payment), r = Monthly interest rate (annual rate / 12), n = Total number of payments (years x 12). Total monthly payment also includes property tax, homeowner's insurance, and PMI if applicable.
Last reviewed: January 2026
Worked Examples
Example 1: Standard 30-Year Mortgage
Example 2: Low Down Payment with PMI
Background & Theory
The Mortgage Calculator - Monthly Payment Estimator applies the following established principles and formulas. A mortgage is a secured loan used to purchase real estate, where the property itself serves as collateral. Understanding how mortgage payments are calculated helps borrowers compare offers, plan budgets, and potentially save hundreds of thousands of dollars over the life of a loan. The standard monthly mortgage payment for principal and interest is determined by the amortization formula: M = P[r(1+r)^n] / [(1+r)^n - 1], where M is the monthly payment, P is the loan principal (home price minus down payment), r is the monthly interest rate (annual rate divided by 12), and n is the total number of monthly payments (loan term in years times 12). This formula produces level payments over the life of the loan, but the proportion allocated to interest versus principal changes with each payment. In the early years, the majority of each payment covers interest because the outstanding balance is large. As the balance decreases, more of each payment reduces principal. This gradual shift is called amortization. For example, on a $300,000 loan at 6.5 percent for 30 years, the monthly principal and interest payment is approximately $1,896. In the first month, roughly $1,625 goes to interest and only $271 to principal. By year 15, the split is roughly equal, and in the final year, nearly the entire payment reduces the balance. The total monthly housing payment typically includes four components, often abbreviated PITI: Principal, Interest, Taxes, and Insurance. Property taxes are assessed annually by local governments, usually ranging from 0.5 to 2.5 percent of assessed value, and are divided into monthly escrow payments collected by the lender. Homeowners insurance protects against damage and liability, and lenders require coverage at least equal to the loan amount. Private Mortgage Insurance (PMI) is an additional cost required when the down payment is less than 20 percent of the purchase price. PMI protects the lender against default, not the borrower, and typically costs between 0.3 and 1.5 percent of the original loan amount annually. PMI can be removed once the loan-to-value ratio reaches 80 percent through regular payments or appreciation, and is automatically terminated by law at 78 percent LTV. Fixed-rate mortgages lock the interest rate for the entire loan term, providing predictable payments. The most common terms are 30 years (lower monthly payment, more total interest) and 15 years (higher monthly payment, substantially less total interest). On a $300,000 loan at 6.5 percent, choosing a 15-year term over a 30-year term saves approximately $200,000 in total interest, but requires a monthly payment roughly 50 percent higher. Adjustable-rate mortgages (ARMs) offer a lower initial rate for a fixed period (commonly 5, 7, or 10 years), after which the rate adjusts periodically based on a market index plus a margin. ARMs carry rate caps that limit how much the rate can increase per adjustment and over the loan's lifetime. ARMs can be advantageous for borrowers who plan to sell or refinance before the adjustment period begins. Mortgage points are fees paid at closing to reduce the interest rate. One discount point costs 1 percent of the loan amount and typically reduces the rate by approximately 0.25 percent. Points make financial sense when the borrower plans to hold the mortgage long enough for the monthly savings to exceed the upfront cost, usually a break-even period of 4 to 7 years. Lenders evaluate borrowers using the debt-to-income (DTI) ratio. The front-end ratio compares monthly housing costs to gross monthly income and should generally be below 28 to 31 percent. The back-end ratio includes all monthly debt obligations and should typically remain below 36 to 43 percent. Credit score, employment history, and assets also significantly influence approval and the interest rate offered.
History
The history behind the Mortgage Calculator - Monthly Payment Estimator traces back through the following developments. The concept of the mortgage dates to ancient civilizations. In Roman law, the hypotheca allowed a debtor to pledge property as security without surrendering possession. The English word mortgage derives from the Old French mort gage, meaning dead pledge, because the arrangement ended (died) either when the debt was repaid or when the lender foreclosed on the property. In medieval England, mortgages were typically short-term arrangements requiring a lump-sum repayment. The modern long-term amortizing mortgage did not emerge until the twentieth century. Before the 1930s, American home loans were commonly five-year balloon mortgages requiring renewal or full repayment, which created catastrophic risk for borrowers when the Great Depression caused banks to refuse renewals. The US federal government transformed mortgage lending during the 1930s. The Federal Home Loan Bank System was created in 1932 to provide liquidity to mortgage lenders. The Federal Housing Administration (FHA), established in 1934, introduced the long-term, fixed-rate, fully amortizing mortgage — the format that dominates American housing finance today. By insuring lenders against default, the FHA made low-down-payment loans viable and standardized underwriting practices nationwide. The GI Bill of 1944 (Servicemen's Readjustment Act) provided zero-down-payment VA-guaranteed home loans to returning veterans, fueling the suburban housing boom of the 1950s and 1960s and dramatically expanding homeownership rates. The creation of Fannie Mae (1938) and Freddie Mac (1970) established the secondary mortgage market, allowing lenders to sell mortgages to investors and free up capital for new lending. The first mortgage-backed securities in the 1970s further expanded available capital for home loans. The Savings and Loan crisis of the 1980s resulted from maturity mismatch — thrift institutions funded long-term fixed-rate mortgages with short-term deposits — combined with deregulation and fraud. Approximately 1,000 institutions failed, costing taxpayers an estimated $160 billion. Adjustable-rate mortgages gained popularity partly as a response to this crisis, shifting interest-rate risk from lenders to borrowers. The 2008 financial crisis was triggered by the collapse of the subprime mortgage market. The originate-to-distribute model incentivized lenders to approve risky loans and sell them into securitization vehicles, leading to widespread defaults when housing prices fell. Millions of foreclosures followed, and the near-collapse of the global financial system prompted the Dodd-Frank Act of 2010, which established qualified mortgage standards, ability-to-repay requirements, and created the Consumer Financial Protection Bureau (CFPB) to oversee mortgage lending practices. Today, the 30-year fixed-rate mortgage remains uniquely American — most other countries primarily use adjustable-rate or shorter-term mortgages. Conforming loan limits, set annually by the Federal Housing Finance Agency, determine the maximum loan size eligible for purchase by Fannie Mae and Freddie Mac. In 2024, the limit for most US counties was $766,550, with higher limits in designated high-cost areas.
Frequently Asked Questions
Reviewed by Sahil, Senior Finance & Tax Editor · Editorial policy
Mortgage Calculator Formula
M = P[r(1+r)^n] / [(1+r)^n - 1]
Where M = Monthly payment (principal & interest), P = Loan principal (home price minus down payment), r = Monthly interest rate (annual rate / 12), n = Total number of payments (years x 12). Total monthly payment also includes property tax, homeowner's insurance, and PMI if applicable.
Mortgage Calculator — Worked Examples
Example 1: Standard 30-Year Mortgage
Problem: You're buying a $350,000 home with 20% down ($70,000), 30-year fixed at 6.5%, property taxes of $3,500/year, and insurance of $1,200/year.
Solution: Loan amount = $350,000 - $70,000 = $280,000\nMonthly rate = 6.5% / 12 = 0.5417%\nMonthly P&I = $280,000 x [0.005417 x (1.005417)^360] / [(1.005417)^360 - 1] = $1,769.84\nMonthly tax = $3,500 / 12 = $291.67\nMonthly insurance = $1,200 / 12 = $100.00\nPMI = $0 (20% down)\nTotal monthly = $2,161.51
Result: Monthly Payment: $2,162 | Total Interest: $357,143 | Total Cost: $777,943
Example 2: Low Down Payment with PMI
Problem: You're buying a $300,000 home with 5% down ($15,000), 30-year fixed at 7%, property taxes of $3,000/year, and insurance of $1,100/year.
Solution: Loan amount = $300,000 - $15,000 = $285,000\nMonthly P&I = $285,000 x [0.005833 x (1.005833)^360] / [(1.005833)^360 - 1] = $1,896.07\nMonthly tax = $3,000 / 12 = $250\nMonthly insurance = $1,100 / 12 = $91.67\nPMI = $285,000 x 0.5% / 12 = $118.75\nTotal monthly = $2,356.49
Result: Monthly Payment: $2,356 | Total Interest: $397,585 | PMI adds $119/month
Mortgage Calculator — Frequently Asked Questions
How is a monthly mortgage payment calculated?
A monthly mortgage payment is calculated using an amortization formula that considers the loan principal, interest rate, and loan term. The formula is M = P[r(1+r)^n]/[(1+r)^n-1], where M is the monthly payment, P is the loan principal, r is the monthly interest rate, and n is the total number of payments. Your total monthly housing payment also includes property taxes divided by 12, homeowner's insurance divided by 12, and possibly private mortgage insurance (PMI) if your down payment is less than 20%. In the early years of your mortgage, most of your payment goes toward interest. As time passes, more of each payment goes toward the principal balance. This is called amortization.
Should I choose a 15-year or 30-year mortgage?
A 15-year mortgage has higher monthly payments but saves significantly on total interest. A 30-year mortgage has lower monthly payments but costs more over the life of the loan. On a $300,000 loan at 6.5%, the 15-year option saves a large amount of interest but requires a much higher monthly payment. Choose the 30-year if you need payment flexibility. Choose the 15-year if you can comfortably afford the higher payment and want to build equity faster.
How does the down payment affect my mortgage?
The down payment directly affects your loan amount, monthly payment, interest paid, and whether you need PMI. A larger down payment means borrowing less, paying less interest, and having lower monthly payments. With a $350,000 home at 6.5% for 30 years: 5% down ($17,500) gives a monthly P&I of $2,101 plus PMI. 10% down ($35,000) gives $1,990/month plus PMI. 20% down ($70,000) gives $1,769/month with no PMI. The 20% down payment option saves roughly $332/month compared to 5% down. Over 30 years, the difference in total interest paid is over $100,000. However, tying up too much cash in a down payment can leave you without an emergency fund, so balance is important.
What credit score do I need for the best mortgage rates?
A FICO score of 760 or higher typically qualifies you for the lowest advertised mortgage rates. Dropping from 760 to 700 can cost you 0.25-0.50% more in interest — on a $400,000 30-year loan, that difference costs roughly $60-$120 more per month and over $25,000 in extra interest. Scores between 620-699 still qualify for conventional loans but at noticeably higher rates. Scores below 580 generally require FHA loans, which accept down payments as low as 3.5% but mandate mortgage insurance for the life of the loan. Before applying, pay down revolving balances to below 30% of credit limits — this alone can boost your score 20-40 points.
How do mortgage points work?
Mortgage discount points are prepaid interest you pay at closing to permanently reduce your loan's interest rate. One point costs 1% of the loan amount — on a $350,000 mortgage, one point costs $3,500 — and typically lowers your rate by 0.20-0.25%. To determine whether buying points makes sense, calculate your break-even period: divide the upfront cost by your monthly savings. For example, $3,500 paid to save $55/month breaks even in about 64 months (5.3 years). If you plan to stay in the home beyond that point, buying points saves money. If you may sell or refinance sooner, keep the cash. Points are tax-deductible in the year of purchase for a primary residence.
When should I consider refinancing my mortgage?
Refinancing makes financial sense when the long-term interest savings exceed the upfront costs. The standard threshold is a rate reduction of at least 0.5-0.75%, though the actual benefit depends on your loan balance and remaining term. Calculate your break-even: if refinancing costs $5,000 and saves $175/month, break-even is about 29 months. You should also consider refinancing to switch from an ARM to a fixed rate for payment certainty, to eliminate PMI if your equity has grown, or to shorten your term from 30 to 15 years to save tens of thousands in interest. Avoid resetting a 25-year-old mortgage back to a new 30-year loan — you may pay more total interest even at a lower rate.