How to Calculate Your Mortgage Payment (2026 PITI Guide)

With over 135,000 people searching "how to calculate mortgage payment" every month, the answer comes down to one framework: PITI. Principal, Interest, Taxes, and Insurance together make up your true monthly housing cost — and skipping any piece can leave you hundreds of dollars short of what you actually owe. This 2026 guide walks through the exact formula, a worked example you can follow, and a free calculator that totals everything in seconds.

What Is a Mortgage Payment? (PITI Explained)

Your monthly mortgage payment is rarely just principal and interest. Lenders and affordability guidelines use PITI — Principal, Interest, Taxes, and Insurance — because that reflects what actually leaves your bank account each month. Principal pays down your loan balance. Interest is the cost of borrowing. Property taxes fund local services and are often collected through an escrow account. Insurance protects the home against fire, wind, and liability claims. If you put less than 20% down, you will also pay private mortgage insurance (PMI) until you reach 20% equity.

Many online tools show only principal and interest, which can understate your payment by $400 to $800 in high-tax states. A $1,996 principal-and-interest quote on a $375,000 home might actually cost $2,500 to $2,700 once taxes, insurance, and PMI are included. Always calculate the full PITI figure before making an offer. For income-based limits, pair this guide with our affordability calculator and 28/36 rule breakdown.

Step 1: Calculate Principal and Interest

Principal and interest use the standard amortization formula: M = P × [r(1+r)^n] / [(1+r)^n − 1]. M is your monthly payment, P is the loan amount (purchase price minus down payment), r is the monthly interest rate (annual rate divided by 12), and n is the total number of payments (loan term in years × 12). For a $375,000 home with 20% down, the loan amount is $300,000. At 7% over 30 years, r = 0.005833 and n = 360, giving a principal-and-interest payment of approximately $1,996 per month.

Early payments are mostly interest because the balance is highest at the start. In month one, roughly $1,750 goes to interest and only $246 reduces principal. By year 15 the split is nearly even; by year 28 most of each payment hits principal. Extra payments in the early years save the most total interest — our amortization schedule calculator shows exactly how each payment splits over time.

Calculate Your Full Payment Right Now

Enter your home price, down payment, rate, and location below to see principal, interest, taxes, insurance, PMI, and total monthly PITI. Adjust any input to compare scenarios — this is the fastest way to answer "how to calculate mortgage payment" for your specific home.

Step 2: Add Property Taxes, Insurance, and PMI

Property taxes equal your assessed home value multiplied by the local effective tax rate, divided by 12 for a monthly figure. On a $375,000 home at 1.2% annually, taxes run $4,500 per year or $375 per month. Rates vary widely — Texas and Illinois often exceed 2%, while Hawaii and Alabama may fall below 0.5%. Use your county assessor's rate or our state presets in the calculator above.

Homeowners insurance typically costs $1,200 to $2,400 per year ($100 to $200 per month) in most inland markets, and significantly more in hurricane, flood, or wildfire zones. If your down payment is under 20%, add PMI — usually 0.5% to 1.5% of the loan amount per year. On a $300,000 loan, PMI adds $125 to $375 per month until you reach 20% equity. Read our PMI guide for strategies to eliminate it faster.

Worked Example: $375,000 Home at 7%

On a $95,000 salary ($7,917 gross monthly), the 20%-down PITI of $2,521 equals 31.8% of gross income — slightly above the 28% front-end guideline but often acceptable with strong credit and low other debts. With 10% down, $2,918 hits 36.8% of gross income, which may require FHA financing or debt reduction. Down payment size directly changes both loan amount and PMI — run both scenarios in the calculator above before you shop.

3 Mistakes That Skew Your Payment Estimate

Mistake 1: Using the lender's principal-and-interest quote as your total payment. Always ask for the full PITI estimate including taxes, insurance, and PMI. Mistake 2: Using national average tax rates instead of your county's actual rate — a 0.5% difference on a $400,000 home changes your payment by $167 per month. Mistake 3: Forgetting HOA fees, which can add $200 to $500 per month in condos and planned communities and count toward DTI limits.