Mortgage Calculator
See your true monthly housing payment — not just principal and interest, but taxes, insurance, PMI, and HOA — plus a full year-by-year amortization schedule and what extra payments would save you.
Formulas: standard amortization math used by US lenders. Last verified: July 2026.
What's actually in a mortgage payment (PITI)
Lenders and real-estate agents quote "principal and interest," but your real monthly bill is PITI:
- Principal — pays down what you borrowed.
- Interest — the lender's charge on the remaining balance.
- Taxes — property tax, usually collected monthly into escrow. Typically 0.5–2.5% of home value per year depending on the state.
- Insurance — homeowners insurance, also usually escrowed.
Two more may apply: PMI (private mortgage insurance, usually ~0.5–1.5% of the loan per year, required when your down payment is under 20% — this calculator adds an estimate automatically and notes when it drops off) and HOA dues.
Why extra payments are so powerful
Early in a 30-year mortgage, most of each payment is interest. Every extra dollar goes straight to principal — shrinking the balance every future interest charge is computed on. On a $320,000 loan at 6.5%, just $200 extra a month cuts 6.6 years and $105,428 in interest off the loan. Run your own numbers above and the calculator shows the exact payoff date and savings.
Before making extra payments, confirm your loan has no prepayment penalty and that extras are applied to principal — and weigh it against higher-return uses of the money (employer 401(k) match first, high-interest debt second).
15-year vs. 30-year
A 15-year term carries a lower rate and dramatically less total interest, but a much higher required payment. A popular middle path: take the 30-year for flexibility and pay it like a 15-year with extras — you keep the option to drop back to the lower payment if life happens.
Here is what that trade-off actually looks like on a $400,000 home with 20% down — a $320,000 loan — using a 6.5% rate for the 30-year and 5.9% for the 15-year, which is a typical spread. Principal and interest only, so it is comparable across rows:
| Option | Monthly (P&I) | Total interest | Paid off in |
|---|---|---|---|
| 30-year at 6.5% | $2,023 | $408,142 | 30 years |
| 15-year at 5.9% | $2,683 | $162,955 | 15 years |
| 30-year + $200/mo extra | $2,223 | $302,714 | 23.4 years |
| 30-year + $500/mo extra | $2,523 | $222,590 | 18.0 years |
Two things stand out. The 15-year saves $245,187 in interest — an enormous number — for $660 more a month. And the "30-year paid like a 15" strategy gets you most of the way there: $500 extra a month costs $160 less per month than the real 15-year and still cuts the loan to 18 years, while leaving you free to drop back to $2,023 in a bad year. What it does not do is match the 15-year's lower rate, which is where roughly $60,000 of the remaining gap comes from.
What one percentage point costs
Rate shopping feels tedious, and the quoted differences sound small. On the same $320,000 loan over 30 years they are not:
| Rate | Monthly (P&I) | Total interest |
|---|---|---|
| 5.5% | $1,817 | $334,093 |
| 6.0% | $1,919 | $370,682 |
| 6.5% | $2,023 | $408,142 |
| 7.0% | $2,129 | $446,428 |
| 7.5% | $2,237 | $485,495 |
Half a percentage point is worth roughly $105 a month and about $38,000 over the life of the loan. Collecting a second and third quote is close to the highest-paid hour of work available to most buyers. The same table also explains why waiting for rates to fall can beat waiting to save a larger deposit — and why refinancing becomes worth the closing costs somewhere around a one-point drop.
How much house can you afford?
The common lender guideline is the 28/36 rule: housing costs under 28% of gross monthly income, and all debt payments combined under 36%. On a $100,000 income, that's about $2,333/month for PITI. Being approved for more doesn't mean it's comfortable — leave room for maintenance (budget ~1% of home value per year), utilities, and savings.
Frequently asked questions
Does this include PMI?
Yes — if your down payment is under 20%, an estimated PMI of 0.8%/year of the loan amount is added, and the calculator notes it drops off once you reach 20% equity (in the schedule, when the balance falls below 80% of the home price).
Is the rate I enter the same as APR?
Close but not identical: the advertised APR includes some fees. For payment estimation, entering your note rate or APR gives nearly the same monthly figure; compare lender offers by APR.
What about ARM (adjustable-rate) loans?
This calculator models fixed-rate loans. For an ARM, run it at the initial rate for a floor and at the rate cap for a ceiling.
Are property tax and insurance estimates included in the defaults?
The defaults ($4,800/yr tax, $1,800/yr insurance) are typical national figures — replace them with your county's actual rate and an insurance quote for real planning.
This tool is for general information only and is not financial advice.
Guides that go deeper
🏠How Your Mortgage Payment Is Actually Calculated
Principal, interest, taxes, insurance and PMI — what each piece is, why early payments are mostly interest, and how rate changes the total.
📊APR vs. Interest Rate: What's the Real Difference?
The interest rate and the APR on a loan are almost never the same number — what APR actually includes and when to ignore it.