How is the monthly mortgage payment calculated?

For a standard fixed-payment (amortizing) loan the payment is M = P·i(1+i)ⁿ / [(1+i)ⁿ − 1], where P is the loan amount, i the annual rate divided by 12 and n the number of monthly payments. For example, $320,000 at 6.5% for 30 years is about $2,022.62 a month before taxes and insurance.

How much does an extra payment save?

An extra payment goes straight to principal, so every later payment carries less interest. Keeping the same payment (shortening the term) usually saves the most interest; keeping the term and lowering the payment frees up monthly cash instead. Turn on the extra payment simulation to see the interest saved and the new number of payments for either choice.

What is the difference between fixed payment and equal principal?

With a fixed payment every installment is the same and early payments are mostly interest. With equal principal you repay the same amount of principal each month plus interest on the remaining balance, so payments start higher and fall steadily, and total interest is lower. The comparison table shows both side by side.

Does the payment include taxes and insurance?

The main figure is principal and interest only. Fill in the annual property tax rate, yearly homeowners insurance and monthly HOA dues to get the total monthly housing cost (often called PITI plus HOA). Private mortgage insurance and closing costs are not included, and your lender’s escrow figures may differ slightly.

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🏠Mortgage Calculator with Amortization Schedule and Extra Payment

Work out what a home really costs each month and over the life of the loan. Enter the home price and down payment percentage (or the loan amount directly), the term and the interest rate to get the monthly principal-and-interest payment, the total interest and the total of all payments. Add property tax, homeowners insurance and HOA dues to see the full monthly housing cost. The comparison table sets a standard fixed payment against an equal-principal loan, where payments start higher but total interest is lower. The extra payment simulator shows what one lump sum after a chosen payment does: keep the payment and pay off years sooner, or keep the term and lower the payment — with the interest saved for each. The amortization schedule summarizes each year and expands to every monthly payment; export it as CSV or send the remaining-balance curve to the graphing tool.

Free · No sign-up · Runs in your browserLast updated: 2026-10-26

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How to use Mortgage Calculator

1Enter the home price and down payment (or the loan amount), the term in years and the interest rate
2Optionally add property tax, insurance and HOA to see the full monthly cost
3Simulate an extra payment, review the amortization schedule and export it as CSV

FAQ

How is the monthly mortgage payment calculated?: For a standard fixed-payment (amortizing) loan the payment is M = P·i(1+i)ⁿ / [(1+i)ⁿ − 1], where P is the loan amount, i the annual rate divided by 12 and n the number of monthly payments. For example, $320,000 at 6.5% for 30 years is about $2,022.62 a month before taxes and insurance.
How much does an extra payment save?: An extra payment goes straight to principal, so every later payment carries less interest. Keeping the same payment (shortening the term) usually saves the most interest; keeping the term and lowering the payment frees up monthly cash instead. Turn on the extra payment simulation to see the interest saved and the new number of payments for either choice.
What is the difference between fixed payment and equal principal?: With a fixed payment every installment is the same and early payments are mostly interest. With equal principal you repay the same amount of principal each month plus interest on the remaining balance, so payments start higher and fall steadily, and total interest is lower. The comparison table shows both side by side.
Does the payment include taxes and insurance?: The main figure is principal and interest only. Fill in the annual property tax rate, yearly homeowners insurance and monthly HOA dues to get the total monthly housing cost (often called PITI plus HOA). Private mortgage insurance and closing costs are not included, and your lender’s escrow figures may differ slightly.