Mortgage Calculator
Calculate precise monthly payments including principal, amortized interest, local property taxes, homeowner's insurance, and PMI. Client-side evaluation with a full amortization schedule.
Amortization Schedule
Yearly progression of loan reduction, capital equity accrual, and diminishing interest load.
Mathematical Formula & Methodology
Standard residential amortization uses an ordinary annuity present value model where the periodic payment is calibrated so the remaining debt equals exactly zero at term maturity:
Lender disclosures are governed by the Truth in Lending Act (Regulation Z, 12 CFR Part 1026) and will include fees this estimate leaves out. Escrow amounts are held constant; real property tax and insurance bills usually rise over time.
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How this calculator works
This calculator uses the standard fixed-rate amortization formula for principal and interest, then adds property tax, home insurance, HOA dues and PMI so you see the full housing cost — not only the loan payment. The loan amount is the home price minus your down payment. PMI is estimated at your chosen rate (0.50% of the loan per year by default) only when you put down less than 20%, and it drops off automatically once the balance reaches 78% of the original home value. Extra principal payments are applied every month and shorten the loan.
By Suhaib Hassan · Formula verified 24 Sep 2026 · How CalculatePilot verifies formulas →
What goes into a monthly mortgage payment
Most lenders quote PITI: principal, interest, taxes, and insurance.
- Principal — the portion of each payment that reduces the outstanding balance.
- Interest — the cost of borrowing. Early payments on a 30-year loan are mostly interest.
- Property tax — county assessments, usually collected monthly into escrow.
- Homeowners insurance — hazard coverage, often escrowed with taxes.
- PMI — required on conventional loans below 20% down, typically 0.3–1.5% of the loan per year.
- HOA dues — set by the association, not the lender.
Biweekly payment power: 26 half-payments a year equal 13 full payments and can shorten a 30-year loan by about 4–6 years. You can model the same effect by entering one-twelfth of a payment as extra principal.
Frequently asked questions
How is a monthly mortgage payment calculated?
Fixed-rate amortization for principal and interest, then monthly tax and insurance. Estimate only — not a lender quote.
Does this include PMI, HOA fees, or closing costs?
HOA is optional. Estimated PMI appears below 20% down. Closing costs are not included.
How much house can I afford?
A common starting point is 28–36% of gross income. Use the House Affordability Calculator.
Should I choose a 15-year or 30-year mortgage?
15-year usually costs less interest and more per month. 30-year keeps the payment lower. The 15-Year Fixed card above shows how much interest you'd save at your inputs.
Does a larger down payment lower my monthly payment?
Yes. It reduces the loan amount and often removes PMI at 20% down.
Are these figures a formal loan offer?
No. Confirm rates and fees with a lender quote.
Should I pay extra on my mortgage or invest that money instead?
On a $400,000 loan at 7%, $300/month extra saves $168,391 in interest and pays off 7.8 years early — a guaranteed 7% return. Investing the same $300/month at 8% would grow to ~$450,389 over the same period. See the full extra-payments-vs-investing breakdown for the math.
When exactly does PMI come off my loan?
By federal law, PMI automatically ends at 78% of your home's original value; you can request removal yourself at 80%. This calculator drops PMI at the 78% point, and extra payments bring that date forward.
Next calculation, in order
1. Affordability · 2. Down payment · 3. Amortization · 4. Refinance · UK repayment · Extra payments vs investing