Mortgage Calculator – Monthly Payment, PMI & Taxes

A mortgage payment is more than just principal and interest. Property taxes, homeowners insurance, private mortgage insurance (PMI) and HOA dues can easily add hundreds of dollars per month on top of your “simple” loan payment. This mortgage calculator helps you estimate the full monthly cost of a U.S. fixed-rate mortgage so you can stress-test your budget before you make an offer.

What This Mortgage Calculator Includes

This tool is designed for standard U.S. fixed-rate mortgages, which is what most homebuyers use. It focuses on conventional loans (not FHA, VA or USDA) and helps you estimate a full monthly payment that looks similar to what you will eventually see on your mortgage statement.

The calculator currently includes:

• Home price and down payment:
  You can enter the down payment in dollars or as a percentage of the purchase price; the other field updates automatically.
• Loan amount, interest rate and term:
  The tool assumes a fixed interest rate for the full term (for example, 30-year fixed), and amortizes the loan with level monthly payments.
• Principal and interest (P&I):
  This is the core loan payment determined by your rate, term and loan amount using the standard mortgage formula (or Excel’s PMT function).
• Property taxes and homeowners insurance:
  You enter annual amounts; the calculator spreads them over 12 months, similar to how an escrow account works on many loans.
• PMI (private mortgage insurance):
  If your down payment is under 20% on a conventional loan, you can enter an annual PMI rate, and the tool estimates initial monthly PMI and for how many months you might pay it (simplified 80% loan-to-value logic).
• HOA dues:
  You can enter a monthly HOA fee, which is added to your total payment.
• Extra monthly principal payment:
  An optional field that adds an additional amount toward principal each month to show a faster payoff and interest savings scenario.
• Amortization schedule and CSV export:
  The calculator shows a summarized amortization table (early months, last months, plus a “…” spacer) and lets you export the full schedule to CSV for deeper analysis.

When all of these components are included, your total monthly mortgage payment often lines up with what lenders and credit bureaus call PITI (principal, interest, taxes and insurance), plus PMI and HOA where applicable.

How to Use the Mortgage Calculator Step by Step

Here is a simple step-by-step way to use the calculator before you start house hunting or while you compare offers from different lenders.

1. Enter the home price and down payment.
   Start with the list price of the home you are considering (or a price range you have in mind) and enter your planned down payment. You can type either the dollar amount or the percentage; the other field will update automatically.
2. Set the interest rate and loan term.
   Use the current rates you are seeing from lenders or pre-approval letters. A 30-year term gives you the lowest principal and interest payment but the highest total interest over time; a 15-year term does the opposite.
3. Add taxes, insurance and HOA dues.
   If you know the annual property tax bill and insurance premium for a specific home, enter them directly. Otherwise, use educated estimates from local tax records, online listings or your real estate agent. Add monthly HOA dues if they apply.
4. Enter PMI if your down payment is under 20%.
   If you are putting less than 20% down on a conventional mortgage, lenders typically require PMI. You can start with a rough rate (for example, around 0.5%–1.0% of the loan amount annually for many borrowers, though it varies by credit score and down payment) or use a PMI estimate from your lender.
5. Consider an extra monthly principal payment.
   If you plan to pay a little extra each month after closing, enter that amount in the “Extra monthly principal payment” field. The calculator will estimate a shorter payoff time and how much interest you might save relative to the standard schedule.
6. Review the results as they update automatically.
   As you adjust the inputs, the calculator will show:
   • The loan amount.
   • The monthly principal and interest payment.
   • The total monthly payment, broken into P&I, PMI, taxes, insurance and HOA.
   • An estimate of your initial PMI and the number of months you might pay it.
   • A summarized amortization schedule and the option to export the full schedule to CSV.
7. Compare scenarios.
   Change one input at a time (for example, price, down payment percentage, rate or term) and see how the results change. This helps you understand how each lever changes your monthly payment and total interest cost.

How Your Mortgage Payment Is Calculated

For a fixed-rate mortgage, the lender uses a standard amortization formula to compute the principal and interest portion of your monthly payment. The payment is structured so that you pay the same amount each month, but in the early years most of that payment is interest, and in the later years more of it becomes principal.

If you prefer to verify the math in Excel or Google Sheets, you can use the built-in PMT function:

=PMT(interest_rate/12, loan_term_years*12, -loan_amount)

This should match the calculator’s principal and interest payment, apart from small rounding differences.

Taxes, Insurance, PMI and HOA: The “Other” Parts of Your Payment

Many homebuyers focus on the principal and interest portion of their mortgage, but for budgeting, the other components can be just as important. Together they form what lenders and financial educators often call PITI: principal, interest, taxes and insurance.

• Property taxes:
  Your city or county charges property taxes based on the home’s assessed value and local tax rates. The calculator spreads your annual tax amount across 12 months so you can see the monthly impact.
• Homeowners insurance:
  A standard homeowners insurance policy protects your home and belongings against covered events like fire or certain storms. Lenders require proof of coverage. Again, the calculator spreads the annual premium over 12 months.
• Private mortgage insurance (PMI):
  On many conventional loans with less than 20% down, PMI protects the lender if you default. It typically adds a monthly cost until you reach around 20%–22% equity, subject to federal law and your loan’s specific terms.
• HOA dues:
  If your home is in a community with a homeowners association, monthly or quarterly dues may cover shared services and maintenance. These can significantly affect affordability, so it is important to include them.
• Escrow account:
  Many lenders collect a portion of taxes and insurance each month in an escrow account and pay those bills on your behalf when they are due. This makes your monthly mortgage payment higher than principal and interest alone but avoids large lump-sum tax and insurance bills.

The calculator’s “Total monthly payment” combines all these elements so you are not surprised later when you see the actual mortgage bill from your servicer.

Extra Payments: Paying Off Your Mortgage Faster

The “Extra monthly principal payment” field lets you model a very common strategy: adding a little extra toward principal every month to pay down your mortgage faster. This does not change your required payment with the lender, but if you consistently pay the extra amount, your loan balance falls faster, and you may pay off the mortgage years early.

Here is how the calculator uses your extra payment:

• It builds a standard amortization schedule using the base principal and interest payment.
• Then it adds your extra principal amount each month (without letting the payment exceed the remaining balance).
• It recalculates how many months it takes to reach a zero balance and sums the total interest paid.
• It compares this “accelerated” schedule with the standard one and shows you an estimated payoff time and interest savings.

In real life, your lender will still show your contractual payment on the statement, and your extra principal amount will appear as an additional line item or separate transaction. The calculator’s approach gives you a clear, math-based estimate of the potential benefit of making these extra payments over time.

How Much Mortgage Can You Comfortably Afford?

Once you have a realistic full monthly payment for a few scenarios, the next question is whether those payments fit your budget. Many lenders and financial planners use the “28/36” debt-to-income rule as a starting point:

• 28% front-end ratio:
  Try to keep your total monthly housing costs (principal, interest, taxes, insurance and HOA dues) at or below about 28% of your gross monthly income.
• 36% back-end ratio:
  Try to keep your total monthly debt payments (housing plus credit cards, auto loans, student loans and other debt) at or below about 36% of your gross monthly income.

These are guidelines, not strict rules, and they can be hard to meet in high-cost markets where home prices, taxes and insurance have risen faster than incomes. Still, they are a useful benchmark for avoiding excessive debt stress and are consistent with how many lenders assess your “ability to repay” under federal rules.

Use this calculator to test several combinations of price, down payment and interest rate. Then compare the total monthly payment against your income and other obligations to decide whether a scenario feels comfortable, not just technically “approvable.”

Ways to Lower Your Monthly Mortgage Payment

If your first scenario feels too expensive, the calculator makes it easy to test ways to reduce your monthly payment before you lock in a loan. Common levers include:

• Choose a less expensive home:
  Reducing the purchase price directly reduces how much you need to borrow, which lowers your principal and interest payment and may reduce PMI as well.
• Increase your down payment:
  Saving or reallocating cash to increase your down payment lowers your loan amount and may eliminate PMI once you reach 20% down on a conventional loan.
• Improve your credit profile and shop for a lower rate:
  Improved credit scores and comparing multiple lenders can sometimes shave your interest rate, which can meaningfully reduce your monthly payment and total interest over the life of the loan.
• Choose a longer loan term (with caution):
  Moving from a 15-year to a 30-year fixed-rate loan generally lowers the monthly payment but increases total interest. Make sure the trade-off aligns with your long-term plans.
• Refine your estimates for taxes, insurance and HOA:
  Using more accurate local estimates can give you a better sense of the true housing cost, and shopping for insurance or considering a community with lower HOA fees can sometimes reduce the non-loan parts of the payment.
• Plan for PMI removal:
  If you start with a smaller down payment, have a plan to remove PMI once your equity reaches the required threshold under your loan’s terms and the Homeowners Protection Act.

Limitations and Assumptions

This mortgage calculator is designed to be transparent and practical, but it is still a simplification of real-world mortgage servicing. Some important limitations:

• Loan type:
  The tool is optimized for conventional fixed-rate mortgages. FHA, VA and USDA loans have different insurance structures and rules that are not fully modeled here.
• PMI rules:
  The PMI estimate uses a simple loan-to-value threshold for cancellation and does not model every nuance of the Homeowners Protection Act, investor overlays or servicer policies.
• Escrow behavior:
  The calculator assumes taxes and insurance are paid evenly over the year. In reality, servicers perform periodic escrow analyses, and your escrow portion can rise or fall if taxes or insurance change.
• Closing costs and points:
  The calculator does not estimate closing costs, lender fees or discount points, which can affect your cash-to-close and the effective interest rate.
• Income, DTI and underwriting:
  The tool does not decide whether you qualify for a loan. Lenders must make their own “ability-to-repay” determination under federal rules, using your income, assets, debts and credit profile.

You should treat the results as a planning aid, then validate them against official documents from your lender, including your Loan Estimate and Closing Disclosure, before you rely on them for major decisions.