How to use this mortgage calculator
Enter your home price and down payment, then add your interest rate and loan term. Include annual property tax and homeowners insurance for a true all-in monthly figure. The calculator updates instantly as you type — no button to press, no sign-up required.
Want to pay off your home sooner? Add an extra monthly principal payment or switch to bi-weekly payments to see how many years you'd shave off and how much interest you'd save versus the standard schedule.
What goes into your monthly payment (PITI)
A typical mortgage payment has four parts, often abbreviated PITI:
- Principal — the portion that pays down what you borrowed.
- Interest — the lender's charge for the loan, highest in the early years.
- Taxes — annual property tax, divided into monthly amounts.
- Insurance — homeowners insurance, also spread monthly.
If your down payment is under 20%, lenders usually add PMI (private mortgage insurance). This calculator detects that automatically, estimates PMI at about 0.75% of the loan per year, and tells you how much more you'd need to put down to avoid it.
How the math works
Principal and interest use the standard amortization formula:
where P is the loan amount, r is the monthly interest rate (annual rate ÷ 12), and n is the total number of monthly payments (years × 12).
For the full breakdown of every formula behind our tools, see our methodology page.
Frequently asked questions
How is a monthly mortgage payment calculated?
Your monthly payment is principal and interest (from the amortization formula above) plus monthly property tax, homeowners insurance, and PMI if your down payment is under 20%.
What is PITI?
PITI stands for Principal, Interest, Taxes, and Insurance — the four parts of a typical monthly payment. Lenders evaluate your full PITI, not just principal and interest, when deciding how much you can borrow.
When do I have to pay PMI?
PMI is generally required on conventional loans when you put down less than 20%, and it's typically removed once you reach 20% equity. The calculator flags it automatically and shows how much more to put down to skip it.
How much do extra or bi-weekly payments save?
Both shorten your term and cut total interest. Enter an extra amount or check the bi-weekly box to see exactly how many years and how much interest you'd save versus the standard schedule.
Related calculators & guides
This calculator is for educational and planning purposes only and provides estimates, not financial advice. Actual loan terms, taxes, insurance, and PMI vary by lender and location. See how we calculate.