How This Mortgage Calculator Works
This calculator shows you the true monthly cost of owning a home. Most online calculators only show Principal & Interest. That is misleading. Your real payment includes property taxes, homeowners insurance, and sometimes PMI and HOA fees. We include all of them by default.
What Is PITI?
PITI stands for Principal, Interest, Taxes, and Insurance. It is the standard way lenders calculate your monthly housing cost.
- Principal: The amount you borrowed. Each payment reduces this balance.
- Interest: The cost of borrowing. It is calculated on your remaining balance, so it is higher at the start and lower over time.
- Taxes: Property tax is charged by your local government. It is usually a percentage of your home's assessed value per year, divided into monthly payments.
- Insurance: Homeowners insurance protects your property. Lenders require it. The annual premium is divided into monthly payments.
What Is PMI?
PMI stands for Private Mortgage Insurance. If your down payment is less than 20% of the home price, most lenders require PMI. It protects the lender if you default. This calculator automatically adds PMI when your down payment is below 20%. PMI is usually removed once you have paid down the loan to 78–80% of the home's value.
What About HOA Fees?
If you buy a condo, townhouse, or a home in a planned community, you may pay Homeowners Association (HOA) fees. These cover shared maintenance, amenities, and sometimes utilities. HOA fees can range from $50 to $500+ per month. This calculator lets you add them manually.
The Formula We Use
We use the standard amortization formula, which is the same method used by lenders and the Consumer Financial Protection Bureau (CFPB):
M = P [ i(1 + i)n ] / [ (1 + i)n − 1 ]
- M = Monthly Principal & Interest payment
- P = Principal loan amount (Home Price − Down Payment)
- i = Monthly interest rate (Annual Rate ÷ 12)
- n = Total number of payments (Loan Term in years × 12)
Property tax is calculated as: (Home Price × Tax Rate) ÷ 12. Insurance is calculated as: Annual Premium ÷ 12. PMI is estimated at 0.5% of the loan amount per year when the down payment is below 20%.
Why We Collect Zero Data
Most mortgage calculators are lead-generation tools. They capture your email, phone number, or browsing behavior and sell it to lenders. We do not. This calculator runs entirely in your browser. No data is sent to any server. No email is required. No phone number is asked. We believe financial tools should be honest, and honesty starts with respecting your privacy.
Frequently Asked Questions
Is this calculator accurate?
Yes, the math follows the CFPB standard amortization formula. However, your actual payment may differ based on your credit score, lender fees, escrow requirements, and local tax rates. Use this as a realistic estimate, not a final quote.
Why is my bank's number different?
Banks may include additional costs such as lender's title insurance, escrow setup fees, or mortgage insurance premiums calculated differently. They may also use a different interest rate based on your credit profile. This calculator gives you the honest baseline.
Does this calculator work for refinancing?
Yes. Enter your remaining loan balance as the "Home Price" and your new down payment as zero (or whatever you are paying). The calculator will show your new monthly payment.
What if I put less than 20% down?
The calculator will automatically add PMI to your monthly payment. PMI typically costs 0.3% to 1.5% of the loan amount per year, depending on your credit score. We use 0.5% as a conservative estimate.
Is my information saved?
No. Nothing is saved. Nothing is transmitted. When you close the page, everything is gone. This is by design.
Disclaimer
This calculator provides estimates for informational purposes only. It does not constitute financial advice. Always consult a licensed mortgage professional before making any financial decision.