Mortgage Calculator

A Mortgage Calculator estimates what a home loan will cost you every month, so you can judge affordability before you ever talk to a lender.

It combines the loan itself with the running costs of owning — property tax, home insurance, and HOA dues — and recalculates instantly in your browser as you adjust the numbers.

What goes into a monthly payment

The core of your payment is principal and interest, the part that actually pays down the loan.

Your loan amount is the home price minus your down payment, and the payment is spread evenly across the full term using the standard amortization formula.

On top of that, this tool adds one-twelfth of your annual property tax, one-twelfth of your annual insurance, and any monthly HOA fee to show a realistic all-in figure.

Down payment: percent or amount

You can enter the down payment either as a percentage of the price or as a flat cash amount, whichever matches how you are thinking about it.

A larger down payment shrinks the loan and lowers every future payment, and it is easy to test both ways in seconds.

To see what a given deposit represents as a share of the price, a Percentage Calculator makes the ratio explicit.

Rate, term, and total cost

Interest rate and term are the two levers that move your payment the most.

A longer term lowers the monthly figure but raises the total interest paid, while a lower rate helps on both fronts.

Because a mortgage is just a large amortizing loan, you can cross-check the principal-and-interest portion with a general Loan Calculator, and if you want to know how many months sit between two dates in your payoff plan, a Date Difference Calculator gives an exact span.

Frequently Asked Questions

How is the monthly mortgage payment calculated?

Principal and interest use the amortization formula: the loan amount times the monthly rate times (1 + monthly rate) to the power of the number of months, divided by that power minus one. The tool then adds one-twelfth of your annual tax and insurance plus any monthly HOA fee to get the total.

Should I enter my down payment as a percent or a dollar amount?

Either works. Use the toggle to switch between percent and amount, and the calculator converts it to the correct down payment either way before working out the loan.

Does this include property tax and insurance?

Yes, if you enter them. Annual property tax and home insurance are divided by 12 and added to the monthly payment, along with any monthly HOA dues. Leave them blank or at zero to see principal and interest alone.

Is my financial data sent anywhere?

No. Every calculation happens locally in your browser with JavaScript. Nothing you type is uploaded, logged, or stored, and the tool keeps working offline once the page has loaded.