What is included in a monthly mortgage payment?

A standard monthly mortgage payment often includes four components, collectively known as PITI: Principal (the amount you borrowed), Interest (the cost of borrowing the money), Taxes (property taxes collected by your lender in escrow), and Insurance (homeowners insurance and, if applicable, private mortgage insurance or PMI).

How much house can I afford?

A common rule of thumb is the 28/36 rule. This suggests that your housing costs (PITI) should not exceed 28% of your gross monthly income, and your total debt payments (including housing, auto loans, student loans, and credit cards) should not exceed 36% of your gross monthly income.

What is an amortization schedule?

An amortization schedule is a complete table of periodic loan payments, showing the amount of principal and the amount of interest that comprise each payment until the loan is paid off at the end of its term. Early in the loan, a larger portion of your payment goes toward interest. In the later years, the majority of your payment pays down the principal.

Should I choose a 15-year or 30-year mortgage?

A 30-year mortgage offers lower monthly payments, which can make a home more affordable or free up cash for other investments. A 15-year mortgage has higher monthly payments, but you will pay significantly less total interest over the life of the loan and build equity much faster.

Finance

Mortgage Calculator

Calculate your monthly mortgage payments including principal, interest, taxes, and insurance (PITI). See your amortization schedule instantly.

The Mortgage Payment formula

Your monthly principal and interest payment is calculated using the standard amortization formula:

 M = P × [ r(1 + r)^n ] / [ (1 + r)^n - 1 ] 

M Monthly Principal & Interest Payment
P Principal Loan Amount (Home Value - Down Payment)
r Monthly interest rate (Annual Rate / 12 / 100)
n Total number of months (30 years = 360 months)

Your total monthly payment will also include property taxes, home insurance, and potentially HOA and PMI fees.

How to use this Mortgage Calculator

Buying a home is one of the most significant financial decisions you will ever make. Our free mortgage calculator is designed to help you estimate your monthly payments quickly and accurately. It calculates your PITI (Principal, Interest, Taxes, and Insurance) to give you a complete picture of what your actual housing costs will be.

To get started, simply input the details of your prospective home purchase. The calculator updates instantly as you type, allowing you to test multiple scenarios—such as different down payment amounts or interest rates—without waiting for a page to reload.

Understanding the inputs

Home Price: The total purchase price of the property you wish to buy.
Down Payment: The upfront amount of money you are paying toward the purchase. This is often expressed as a percentage of the home price. A down payment of 20% or more typically allows you to avoid paying Private Mortgage Insurance (PMI).
Loan Term: The number of years you have to pay back the loan. The most common terms in the US are 30 years and 15 years.
Interest Rate: The annual cost to borrow the money, expressed as a percentage. Even a small change in the interest rate can significantly impact your monthly payment and the total cost of the loan.
Property Taxes (Optional): The annual tax levied by your local government based on the value of your property. If entered, we will divide this by 12 to show the monthly cost.
Home Insurance (Optional): Your annual homeowners insurance premium.
HOA Fees (Optional): Monthly fees paid to a Homeowners Association, common in condos and planned communities.

The Formula Behind the Calculation

The core of any mortgage calculation is determining the monthly principal and interest payment. While property taxes, insurance, and HOA fees are simply added as flat monthly costs, the principal and interest payment requires a specific mathematical formula.

The formula used to calculate the fixed monthly payment (M) for a fully amortizing loan is:

M = P * [ r(1 + r)^n ] / [ (1 + r)^n - 1 ]

Where:

M = Total monthly principal and interest payment
P = Principal loan amount (Home Price minus Down Payment)
r = Monthly interest rate (Annual interest rate divided by 12, then divided by 100)
n = Total number of payments (Loan term in years multiplied by 12)

Example Calculation

Imagine you are purchasing a house for $400,000. You plan to put down 20% ($80,000), leaving you with a principal loan amount (P) of $320,000. You secure a 30-year fixed-rate mortgage at an annual interest rate of 6.5%.

Calculate the monthly interest rate (r): r = 6.5% / 12 / 100 = 0.0054166...
Calculate the total number of payments (n): n = 30 years * 12 months/year = 360 payments
Apply the formula: M = $320,000 * [ 0.0054166 * (1 + 0.0054166)^360 ] / [ (1 + 0.0054166)^360 - 1 ] M = $2,022.62

Your monthly payment for principal and interest alone would be $2,022.62. Over the 30-year term, you would pay a total of $408,143 in interest, making the total cost of the loan (principal + interest) $728,143. Note that this example does not include property taxes, homeowners insurance, or HOA fees, which would be added on top of this figure to determine your total monthly cash outlay.

If you are looking for related financial tools, check out our loan calculator for personal loans or our home affordability calculator to work backwards from a target monthly payment. Additionally, if you already own a home and are considering lowering your interest rate, you can explore our refinance calculator to see if the closing costs make sense for your current loan.

Important Considerations for Homebuyers

When using this calculator, remember that your PITI payment is just one aspect of homeownership. Lenders will also scrutinize your credit score, debt-to-income (DTI) ratio, and employment history before granting final approval. While our tool gives you a highly accurate estimate of the core mathematics behind a traditional fixed-rate loan, it cannot account for volatile adjustable-rate mortgages (ARMs) or lender-specific origination fees. Always ensure you are comparing multiple lenders to get the best possible interest rate, as even a quarter-point difference can save you tens of thousands of dollars over a thirty-year timeline.

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Results are estimates for educational purposes only and may not reflect all factors in your specific situation. This is not financial advice. Consult a qualified financial adviser for personalised guidance.