Mortgage Calculator: Monthly PITI & Amortization

Calculated using standard mathematical amortization formulas and Consumer Financial Protection Bureau (CFPB) mortgage disclosure guidelines.

Use this comprehensive mortgage payment calculator to estimate your exact monthly payment, total interest, and out-of-pocket home ownership expenses. Factor in property taxes, insurance, PMI, and HOA fees, or simulate extra payments to see how much interest and time you can save.

How to use this calculator?

  1. Enter the home price — the full purchase price of the property.
  2. Enter your down payment as a dollar amount or a percentage (e.g. 20%). The loan amount is automatically calculated.
  3. Set the annual interest rate and loan term (typically 15, 20, or 30 years).
  4. Adjust property taxes, homeowners insurance, PMI, HOA fees, and maintenance costs to get the true total out-of-pocket monthly housing expense.
  5. Experiment with Extra Payments (monthly, yearly, or lump-sum) to see how many years and tens of thousands of dollars in interest you can save.
  6. Review the Biweekly Payback section to compare paying half-payments every two weeks (26 times a year), which automatically cuts years off your mortgage.

Formula & calculation method

How the monthly payment is calculated

M = P × [ r(1 + r)^n ] / [ (1 + r)^n − 1 ]

M = monthly P&I payment · P = loan principal (price − down payment) · r = monthly interest rate (annual ÷ 12) · n = total number of monthly payments (years × 12)

Step-by-step calculation example

For a $400,000 home with 20% ($80,000) down at 6.81% over 30 years: P = $320,000, r = 0.005675, n = 360 → monthly payment = $2,088.29.

Key insights to remember

How to interpret your results?

Principal & Interest vs Total Out-of-Pocket

Your mortgage payment (P&I) is what repays the lender. Your true total monthly housing cost (PITI) also includes property taxes, insurance, HOA fees, and routine maintenance.

Payment-to-Income (28% Front-End DTI)

Under standard underwriting guidelines, your total monthly housing cost should not exceed 28% of your gross monthly household income.

Extra Payments Compounding

Because extra payments go 100% directly toward reducing principal, they stop future compounding interest immediately, creating exponential lifetime savings.

Biweekly Acceleration Effect

Switching to biweekly payments aligns with 26 paychecks a year, seamlessly retiring your debt years ahead of schedule without feeling like a major budget sacrifice.

Frequently asked questions

What does PITI stand for?
PITI stands for Principal, Interest, Taxes, and Insurance. It represents the comprehensive monthly cost of owning a mortgaged home.
How does extra payment save so much interest?
Mortgage interest is calculated on the remaining loan balance. Every dollar of extra payment directly knocks down principal, permanently eliminating interest charges on that dollar for the rest of the loan term.
When does PMI get removed?
Under the federal Homeowners Protection Act, lenders must automatically terminate PMI once your loan balance reaches 78% of the original purchase price, and you can request removal once it drops below 80%.
How does biweekly mortgage payment work?
Instead of 12 monthly payments per year, you pay half your monthly payment every two weeks. Since there are 52 weeks in a year, you make 26 half-payments, which equals 13 full payments per year — one full extra payment every year.
Can I toggle between annual and monthly amortization?
Yes. The amortization schedule below features both annual and monthly schedules with detailed breakdown of interest, principal, and ending balance.

Related calculators

See all finance calculators · Explore all online calculators