Calculate your full monthly mortgage payment broken into principal and interest, property tax, homeowners insurance, and PMI, plus total interest over the life of the loan.
Total monthly payment
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Principal & interest—
Property tax—
Homeowners insurance—
PMI—
Loan amount
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Total interest (life of loan)
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How It Works
The loan amount is the home price minus the down payment (down payment percentage times home price). The principal-and-interest portion uses the standard amortization formula: M = P × r(1+r)^n / ((1+r)^n − 1), where r is the monthly rate and n is the number of months.
Monthly property tax is the annual tax divided by 12. Monthly homeowners insurance is the annual premium divided by 12. Monthly PMI is the PMI rate times the loan amount divided by 12, applied when the down payment is under 20%.
Your total monthly payment is the sum of all four parts. Total interest is the sum of every interest payment over the full loan term.
Worked example: a $450,000 home with 20% down ($90,000) leaves a $360,000 loan. At 6.75% for 30 years (360 months), the monthly rate is 0.005625, so P&I = 360000 × 0.005625 × (1.005625)^360 / ((1.005625)^360 − 1) ≈ $2,331. Add $450/mo property tax, $125/mo insurance, and $0 PMI (20%+ down) for a total of about $2,906/mo. Over 30 years the P&I payments total roughly $839,160, of which about $479,160 is interest (the $839,160 total minus the $360,000 loan amount).
Frequently Asked Questions
When is PMI required?
Private mortgage insurance is typically required when your down payment is less than 20% of the home price. It usually cancels automatically once the loan balance reaches 78% of the original value.
Are property taxes and insurance included in my payment?
Most lenders collect property tax and insurance as part of your monthly payment and hold them in an escrow account, so the total here reflects what you actually pay each month.
Does this include closing costs?
No. Closing costs are paid upfront at the loan closing and are not part of the ongoing monthly payment calculated here.
How much does a 1% rate change affect my payment?
On a $360,000 30-year loan, each 1% change in the interest rate shifts the principal-and-interest portion by roughly $230–240 per month. Over 30 years that adds up to over $80,000 in interest per percentage point.
What is the difference between APR and interest rate?
The interest rate is the cost of borrowing the principal. The APR includes the interest rate plus certain lender fees and points, so it reflects the true yearly cost of the loan. This calculator uses the interest rate, not the APR.
How does a shorter loan term change the numbers?
A 15-year term raises the monthly P&I payment but cuts total interest dramatically because the balance is paid down faster and the rate is often lower. On the example above, a 15-year loan at 6% roughly doubles the monthly P&I but cuts lifetime interest from ~$479K to ~$187K.