About the Mortgage Calculator
The payment a lender quotes is usually principal and interest only, while your actual monthly housing cost often includes escrow for property taxes and insurance. This calculator shows both, so there are no surprises.
Every assumption is an input you can change. For comparing loans, the principal-vs-interest chart and amortization schedule show how much of the total you pay in interest.
How It Works
The loan amount is the home price minus your down payment. Principal and interest use the standard fixed-rate formula with monthly payments; property tax and insurance are divided by 12, and HOA and PMI are added as monthly amounts.
In the amortization schedule, each payment's interest is the remaining balance times the monthly rate; the rest reduces the principal. The final payment is adjusted so the balance ends at exactly $0.
Formula
- Lloan amount = home price − down payment
- rmonthly rate = annual rate ÷ 12
- nnumber of payments = years × 12
Example
A $400,000 home with $80,000 down (20%), a 6.5% fixed rate for 30 years, $4,800 a year in property tax, and $1,500 a year for insurance.
Inputs
- Loan amount
- $320,000
- Rate / term
- 6.50% · 30 years
- Tax + insurance
- $525/mo
Results
- Principal & interest
- $2,022.62
- Total monthly payment
- $2,547.62
- Total interest
- $408,142.36
Assumptions & Limitations
- Fixed-rate loan with monthly payments; adjustable-rate loans change over time.
- Property tax, insurance, HOA and PMI stay constant; in reality they often rise, and PMI can usually be removed once enough equity is built.
- Not included: closing costs, points, prepayments, and escrow cushions.
- Rates are your input; this calculator does not supply or recommend mortgage rates.
Understanding Your Results
- Estimated Total Monthly Payment: Principal, interest, taxes, insurance, HOA and PMI combined.
- Total Interest: All interest paid over the full term if you make every scheduled payment.
- Total Loan Cost: Loan amount plus total interest — what the loan costs over its life, excluding taxes and insurance.