How to use Mortgage Calculator
This mortgage calculator estimates your monthly principal-and-interest payment and shows the full cost of a home loan over its lifetime. Add a down payment, property taxes, insurance and HOA fees for an all-in monthly figure, then use the amortization schedule and balance chart to see exactly how much goes to interest versus principal each year. Model extra payments to find out how much interest you could save and how many years you could cut from your term.
- Enter the home price (or loan amount) and your down payment.
- Set the annual interest rate and loan term (commonly 15 or 30 years).
- Optionally add property tax, home insurance, PMI and HOA for a true monthly cost.
- Add an extra monthly payment to see interest saved and a shorter payoff date.
- Review the payment breakdown, balance-over-time chart and year-by-year schedule.
Your data never leaves your device — 100% private processing.
How the monthly payment is calculated
A fixed-rate mortgage payment is computed with the standard amortization formula M = P · [ r(1+r)^n ] / [ (1+r)^n − 1 ], where P is the principal (loan amount minus down payment), r is the monthly interest rate (annual rate ÷ 12) and n is the total number of monthly payments (years × 12). Early payments are mostly interest; as the balance falls, more of each payment goes to principal — which is why the balance curve starts shallow and steepens over time.
Principal, interest, taxes and insurance (PITI)
Lenders look at your total monthly housing cost, often abbreviated PITI: principal, interest, property taxes and homeowners insurance. If your down payment is under 20%, most conventional loans also add private mortgage insurance (PMI) until you reach about 20% equity. Many buyers also pay HOA dues. Including these gives a realistic "out-the-door" monthly number rather than principal and interest alone.
| Component | What it covers | Typical range |
|---|---|---|
| Principal & interest | Repaying the loan plus the cost of borrowing | Largest portion |
| Property tax | Local government tax on the home | 0.3%–2.2% of value/yr |
| Home insurance | Protects the structure and belongings | $1,000–$3,000/yr |
| PMI | Required when down payment < 20% | 0.3%–1.5% of loan/yr |
| HOA | Community/condo association dues | $0–$700/mo |
How extra payments save money
Any amount paid above the scheduled payment goes straight to principal, which reduces the balance that future interest is charged on. Even a small recurring extra payment can shorten a 30-year loan by several years and save tens of thousands in interest. Use the extra-payment field to compare scenarios side by side.
Worked examples
30-year loan
Inputs: $300,000 · 6.5% · 30 yr · $60k down
Result: $1,517/mo P&I · ~$306k total interest
With $200 extra/mo
Inputs: same loan + $200 extra monthly
Result: Pay off ~6 years early · save ~$78k interest
Glossary
- Amortization
- The schedule by which a loan is repaid through regular payments split between principal and interest.
- APR
- Annual percentage rate — the yearly cost of the loan including certain fees, useful for comparing offers.
- Escrow
- An account your lender uses to collect and pay property taxes and insurance on your behalf.
- PMI
- Private mortgage insurance, charged when the down payment is below ~20% of the home price.
- Principal
- The amount you actually borrowed, separate from the interest charged on it.
Related reading
Frequently Asked Questions
Why use Mortgage Calculator?
- See your true monthly cost including taxes, insurance, PMI and HOA — not just principal and interest
- Full amortization schedule shows the interest-vs-principal split for every year of the loan
- Model extra monthly payments to see exactly how much interest you save and how many years you cut
- Compare 15- vs 30-year terms and different rates side by side before talking to a lender
Common use cases
- Work out whether you can comfortably afford a specific home price
- Decide between a 15-year and 30-year mortgage on the same property
- See how much a 0.5% rate change adds over the life of the loan
- Plan extra principal payments to pay off your mortgage years early
- Estimate the all-in PITI payment before getting pre-approved
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