Mortgage Calculator
Calculate monthly payment, total interest, and a quick amortization preview.
| # | Date | Payment | Principal | Interest | Balance |
|---|---|---|---|---|---|
| Run a calculation to see the schedule. | |||||
Use this Mortgage Calculator to estimate your monthly mortgage payment, total interest, payoff date, and the effect of optional property taxes, homeowners insurance, PMI, and extra principal payments.
Important: This calculator provides an estimate for mortgage planning. Your actual payment and loan costs depend on the mortgage terms, lender fees, taxes, insurance, and other costs shown in your official loan documents.
Mortgage Payment Calculation
If you enter a home price and down payment:
Loan amount = home price − down payment
If you enter a loan amount directly, the calculator uses that value instead.
For a standard fixed-rate mortgage, the monthly principal-and-interest payment is calculated as:
M = P × [r(1 + r)n] ÷ [(1 + r)n − 1]
Where:
- M = monthly principal and interest payment
- P = mortgage principal
- r = monthly interest rate
- n = total number of monthly payments
Monthly interest rate = annual interest rate ÷ 12 ÷ 100
Total Monthly Mortgage Estimate
The calculator can add optional housing costs to the principal-and-interest payment:
Monthly property tax = annual property tax ÷ 12
Monthly insurance = annual homeowners insurance ÷ 12
Total monthly estimate = principal and interest + property tax + homeowners insurance + PMI
The amortization calculation itself applies to the mortgage principal and interest. Taxes, insurance, and PMI do not reduce the mortgage balance.
Example
Suppose a home costs $350,000 and you make a $20,000 down payment. The mortgage has a 6.5% fixed interest rate and a 30-year term.
Loan amount = $350,000 − $20,000 = $330,000
The estimated monthly principal-and-interest payment is:
≈ $2,085.82
Now suppose you also enter:
- Annual property tax: $3,600
- Annual homeowners insurance: $1,200
- Monthly PMI: $75
Monthly property tax = $3,600 ÷ 12 = $300
Monthly insurance = $1,200 ÷ 12 = $100
The estimated total monthly payment becomes:
$2,085.82 + $300 + $100 + $75 = $2,560.82
How Amortization Works
Each scheduled mortgage payment is divided between principal and interest.
Monthly interest = remaining loan balance × monthly interest rate
Principal paid = scheduled payment − monthly interest
Early in a typical fixed-rate mortgage, more of the payment goes toward interest because the outstanding balance is higher. As the balance falls, less interest is charged and more of each payment goes toward principal.
If you enter an extra monthly payment, the calculator applies that amount toward principal in the estimate. This can reduce future interest and shorten the estimated payoff period.
Important Notes
- Use the mortgage interest rate, not APR, for the principal-and-interest payment calculation.
- APR is useful when comparing broader borrowing costs because it can include certain fees and other charges.
- Property taxes and homeowners insurance can change over time even when the principal-and-interest payment on a fixed-rate mortgage stays the same.
- PMI may apply to some conventional mortgages when the down payment is less than 20%, although requirements depend on the loan.
- HOA dues, maintenance, utilities, closing costs, flood insurance, lender fees, and other ownership expenses are not included unless specifically represented by the calculator.
- Extra-payment estimates assume the additional payment is applied to principal. Confirm how your mortgage servicer handles extra payments.
- Adjustable-rate, interest-only, balloon, FHA, VA, USDA, and other mortgage structures may involve different payment or insurance rules.
Sources
- Consumer Financial Protection Bureau — How Mortgage Lenders Calculate Monthly Payments
- Consumer Financial Protection Bureau — Principal and Interest vs. Total Monthly Payment
- Consumer Financial Protection Bureau — Mortgage Interest Rate vs. APR
- Consumer Financial Protection Bureau — Private Mortgage Insurance