Quick Answer: Estimate a monthly mortgage payment including principal and interest, property tax, homeowners insurance, PMI, HOA fees, total interest, and amortization.
How This Calculator Works
Mortgage affordability depends on more than the loan payment. This calculator separates principal and interest from recurring ownership costs so the full monthly housing payment is easier to compare.
Worked Scenario: Scenario: Buying a $400,000 Home
A buyer purchases a $400,000 home with 20% down, a 30-year term, and a 6.5% fixed interest rate.
Scenario Inputs
- Home price: $400,000
- Down payment: $80,000
- Mortgage rate: 6.5%
Outcome: The loan amount is 320,000. Principal and interest are about 2,023 per month before adding property taxes, insurance, HOA dues, or mortgage insurance.
Formula and Methodology
Monthly P&I = P * [r(1 + r)^n] / [(1 + r)^n - 1]
Total monthly payment = P&I + property tax + insurance + PMI + HOA
Loan amount = Home price - Down payment
Variables
- P: Mortgage principal after down payment
- r: Monthly interest rate
- n: Total number of monthly payments
- PMI: Private mortgage insurance estimate when down payment is below 20%
Assumptions
- Interest rate remains fixed for the full loan term.
- Payments are made monthly and amortize the loan to zero by the end of the term.
- Property tax, insurance, PMI, and HOA assumptions remain constant.
Limitations
- Does not include closing costs, lender fees, escrow changes, rate resets, points, or tax deductions.
- PMI rules vary by lender and jurisdiction; this calculator applies a simple annual percentage estimate.
Practical FAQs
What is included in a mortgage payment?
A full housing payment can include principal, interest, property taxes, homeowners insurance, private mortgage insurance, and HOA dues. Lenders often refer to principal, interest, taxes, and insurance as PITI.
How does the down payment affect PMI?
Many conventional mortgages require PMI when the down payment is below 20%. This calculator estimates PMI from the loan amount and annual PMI rate.
Why is total interest so high on a long mortgage?
A 30-year mortgage spreads repayment over 360 monthly payments. Early payments are interest-heavy because the outstanding principal is still large.