🏠 Mortgage Calculator
A mortgage calculator with full PITI, the exact month PMI ends under federal law, the crossover month, and what extra principal actually saves.
- Principal and interest
- $2,275.44
- Property tax
- $400.00
- Home insurance
- $150.00
- PMI (while it applies)
- $180.00
- Total interest over the loan
- $459,160
- Interest per dollar borrowed
- $1.28
- Principal first exceeds interest
- month 233 (Jan 2046)
- Payoff
- month 360 (Aug 2056)
| Year | Interest | Principal | Balance |
|---|---|---|---|
| 1 | $23,282 | $4,024 | $355,976 |
| 2 | $23,012 | $4,293 | $351,683 |
| 3 | $22,725 | $4,581 | $347,102 |
| 4 | $22,418 | $4,888 | $342,214 |
| 5 | $22,090 | $5,215 | $337,000 |
| 6 | $21,741 | $5,564 | $331,435 |
| 7 | $21,368 | $5,937 | $325,498 |
| 8 | $20,971 | $6,334 | $319,164 |
| 9 | $20,547 | $6,759 | $312,405 |
| 10 | $20,094 | $7,211 | $305,194 |
| 11 | $19,611 | $7,694 | $297,500 |
| 12 | $19,096 | $8,210 | $289,290 |
| 13 | $18,546 | $8,759 | $280,531 |
| 14 | $17,959 | $9,346 | $271,185 |
| 15 | $17,333 | $9,972 | $261,213 |
| 16 | $16,666 | $10,640 | $250,573 |
| 17 | $15,953 | $11,352 | $239,221 |
| 18 | $15,193 | $12,113 | $227,108 |
| 19 | $14,382 | $12,924 | $214,184 |
| 20 | $13,516 | $13,789 | $200,395 |
| 21 | $12,592 | $14,713 | $185,682 |
| 22 | $11,607 | $15,698 | $169,984 |
| 23 | $10,556 | $16,750 | $153,234 |
| 24 | $9,434 | $17,871 | $135,363 |
| 25 | $8,237 | $19,068 | $116,295 |
| 26 | $6,960 | $20,345 | $95,950 |
| 27 | $5,598 | $21,708 | $74,242 |
| 28 | $4,144 | $23,162 | $51,081 |
| 29 | $2,593 | $24,713 | $26,368 |
| 30 | $938 | $26,368 | $0 |
What Mortgage Calculator Does
The number a mortgage calculator gives you is usually not the number that leaves your account. Principal and interest are the loan; property tax, home insurance, any HOA fee and — below 20% down — mortgage insurance are the rest of the payment, and together they routinely add a third to the total. A quote of principal and interest alone is not a housing budget.
The second thing calculators get wrong is PMI. Almost all of them charge it for the full thirty years. Federal law says otherwise: the Homeowners Protection Act gives you the right to request cancellation once the scheduled balance reaches 80% of the original purchase price, requires the servicer to terminate it automatically at 78%, and ends it regardless the month after the midpoint of the schedule. On a typical 10%-down purchase that is around nine years of PMI, not thirty — a difference of tens of thousands of dollars.
The third is where the money actually goes. Interest is charged on the outstanding balance, which is largest at the start, so the first payment on a $360,000 loan at 6.5% is $1,950 interest against $325 of principal. Principal does not overtake interest until around month 233. That crossover is the single most useful thing to understand about a long amortizing loan, and almost nothing shows it.
This calculator computes the full payment, finds all three PMI dates, marks the crossover month, and shows what extra principal returns — which, on the default scenario, is about $1.90 of interest saved per extra dollar paid.
How to Use Mortgage Calculator
- Enter the home price, down payment, interest rate and term
- Add annual property tax, home insurance and any HOA fee so the payment is a real PITI figure
- Set the PMI rate if you are putting down less than 20% — the calculator works out when it ends
- Add extra monthly principal to see the payoff date move and the interest saving
Formula Used by Mortgage Calculator
The monthly payment
M = P × [ r(1+r)ⁿ ] ÷ [ (1+r)ⁿ − 1 ]
- P
- Loan amount — the price minus the down payment
- r
- Monthly rate: the annual rate divided by 12
- n
- Total payments: years × 12
Worked example
A $320,000 loan over 30 years at 6.792%
- r = 0.06792 ÷ 12 = 0.00566
- n = 360
- M = 320,000 × [0.00566 × 1.00566³⁶⁰] ÷ [1.00566³⁶⁰ − 1]
Result: $2,084.46 a month, and $430,406 of interest over the term
How each payment splits
interest = balance × r · principal = M − interest
- Why it shifts
- The balance falls each month, so the interest share falls and the principal share rises
- Crossover
- The month principal first exceeds interest — much later than people expect
Worked example
A $360,000 loan at 6.5%, payment $2,275.44
- Month 1: interest 360,000 × 0.005417 = $1,950, principal $325
- Month 233: the two cross over
- Month 360: interest $12, principal $2,263
Result: Nineteen and a half years before more than half the payment builds equity
The full PITI payment
PITI = principal + interest + tax/12 + insurance/12 (+ HOA + PMI)
- Escrow
- Tax and insurance are usually collected monthly by the servicer and paid out annually
- PMI
- Typically 0.3%–1.9% of the loan per year, charged only below 20% down
Worked example
A $400,000 home, 10% down, 6.5%, $4,800 tax, $1,800 insurance, 0.6% PMI
- P&I on $360,000: $2,275.44
- Tax: $400 · Insurance: $150
- PMI: 360,000 × 0.006 ÷ 12 = $180
Result: $3,005.44 a month — 32% more than the principal-and-interest figure alone
When PMI ends, under federal law
Request at 80% LTV · automatic at 78% LTV · and the month after the schedule midpoint
- Original value
- All three are measured against the original purchase price, not a later appraisal
- Scheduled balance
- Based on the original amortization schedule, so extra payments do not move these dates
Worked example
The same $360,000 loan on a $400,000 home
- 80% of 400,000 = $320,000, reached month 95
- 78% = $312,000, reached month 109
- Midpoint rule: month 181
Result: PMI ends at month 109 — $19,620 in total, not the $64,800 a full-term calculation gives
Where the money goes on a $360,000 loan at 6.5%
Thirty years, payment $2,275.44. Note how little of the balance moves in the first decade — this is what an amortizing loan looks like from the inside.
| Month | Interest | Principal | Balance after |
|---|---|---|---|
| 1 | $1,950 | $325 | $359,675 |
| 60 (year 5) | $1,828 | $448 | $337,000 |
| 120 (year 10) | $1,656 | $619 | $305,194 |
| 233 (crossover) | $1,136 | $1,140 | $208,547 |
| 300 (year 25) | $639 | $1,637 | $116,295 |
| 360 (final) | $12 | $2,263 | $0 |
What each extra $100 a month is worth
The same loan, with extra principal added from month one. Every extra dollar retires debt that would otherwise have accrued interest for the rest of the term, which is why the return is so large — and why it tapers as the loan shortens.
| Extra per month | Paid off in | Total interest | Interest saved | Saved per extra $1 |
|---|---|---|---|---|
| $0 | 30.0 years | $459,160 | — | — |
| $100 | 26.6 years | $396,252 | $62,908 | $1.97 |
| $200 | 23.9 years | $350,243 | $108,917 | $1.90 |
| $300 | 21.8 years | $314,756 | $144,404 | $1.84 |
| $500 | 18.8 years | $263,030 | $196,131 | $1.74 |
| $1,000 | 14.0 years | $188,556 | $270,604 | $1.61 |
Rate sensitivity on the same loan
$360,000 over 30 years. A single percentage point moves the payment by about $242 a month and the lifetime interest by roughly $87,000 — which is why shopping the rate is worth more than almost anything else on this page.
| Rate | Monthly P&I | Total interest | Interest per $1 borrowed |
|---|---|---|---|
| 5.00% | $1,933 | $335,721 | $0.93 |
| 5.50% | $2,044 | $375,855 | $1.04 |
| 6.00% | $2,158 | $417,017 | $1.16 |
| 6.50% | $2,275 | $459,160 | $1.28 |
| 7.00% | $2,395 | $502,232 | $1.39 |
| 7.50% | $2,517 | $546,182 | $1.52 |
| 8.00% | $2,642 | $590,959 | $1.64 |
Term length on the same $360,000
At an identical 6.5% rate, to isolate the effect of the term alone. In practice shorter terms usually carry lower rates, widening the gap further.
| Term | Monthly P&I | Total interest | Against 30 years |
|---|---|---|---|
| 30 years | $2,275.44 | $459,160 | — |
| 15 years | $3,135.99 | $204,478 | $861 more a month, $254,682 less interest |
How to Read Your Result
Principal and interest is not your housing payment
Tax, insurance and any HOA fee are not optional extras — they are due whether or not the calculator mentions them, and they keep rising after the mortgage payment has been fixed for thirty years. On a $400,000 home with $4,800 of tax and $1,800 of insurance, the escrow portion alone is $550 a month. Budgeting from a principal-and-interest quote is the single most common way people end up house-poor, and it is also why lenders qualify you on the full PITI figure rather than the loan payment.
PMI has an expiry date, and you may have to ask for it
The 78% automatic termination happens on its own; the 80% cancellation does not. It requires a written request, a clean payment history, no junior liens, and evidence the property has not fallen below its original value. The gap between those two dates is real money — on the default scenario here, fourteen months of PMI — and nobody will remind you. Diarize the 80% month from your original schedule and write in. Note also that all three dates are computed from the original schedule, so paying extra shortens the loan without moving the PMI dates at all.
The crossover month explains the first decade
Because interest is charged on the outstanding balance, the early payments are almost entirely interest. On a 30-year loan at 6.5% the crossover — where principal first exceeds interest in a single payment — falls around month 233, nineteen years in. That is why five years of payments leaves the balance barely dented, why selling early rarely recovers what feels like it should be there, and why extra principal in year one is worth so much more than extra principal in year twenty.
Extra payments have a knowable return
An extra dollar of principal today saves every future dollar of interest that would have accrued on it, which at 6.5% over a full term works out to roughly $1.90 saved per $1 paid. That is a guaranteed, tax-free return equal to your mortgage rate, which is a genuinely competitive number — but it is illiquid, since money in the house is hard to get back out. The honest comparison is against your other debts first, any employer retirement match second, and only then the mortgage.
The rate matters more than the term
A single percentage point on a $360,000 loan is about $242 a month and $87,000 over thirty years. Shopping three or four lenders is the highest-value hour available in this whole process, and the CFPB publishes rate data by state showing how wide the spread genuinely is. Discount points are the same trade in another form: paying interest up front to lower the rate, worth it only if you keep the loan past the break-even.
What is deliberately not here
Closing costs are excluded because they are settlement fees rather than part of the monthly payment — commonly a few percent of the purchase price, paid once. Also absent: maintenance, which rules of thumb put near 1% of the home value annually, utilities, and the mortgage interest deduction, which only benefits you if you itemize and has been worth far less to most households since the standard deduction rose. Each of those changes the real cost of owning, in both directions.
Limitations & Accuracy Notes
- This models a fixed-rate mortgage. Adjustable-rate loans reset on a schedule tied to an index, and the payment after the fixed period cannot be projected from these inputs.
- Closing costs, discount points, origination fees and prepaid items are not included. They are one-off settlement costs, commonly a few percent of the purchase price.
- Property tax and insurance are entered as fixed annual amounts. Both generally rise over time, so a payment that is affordable today may not be in a decade — a real effect this model does not project.
- PMI dates follow the federal Homeowners Protection Act, which covers most conventional loans. FHA mortgage insurance works differently: on most current FHA loans with under 10% down it lasts the life of the loan and cannot be canceled by reaching an LTV threshold.
- Extra payments are assumed to reduce principal immediately and without penalty. Some loans carry prepayment penalties, and some servicers apply unlabelled extra funds to the next payment instead of principal — say so in writing.
- Nothing here is a loan offer, an affordability assessment or financial advice. Your actual rate depends on credit, loan type, points and lender, and only a Loan Estimate from a lender is binding.
Frequently Asked Questions
What does PITI mean?
When does PMI drop off?
Do extra payments really save that much?
Why is almost all of my early payment interest?
Is a 15-year mortgage worth the higher payment?
Does this include closing costs?
References & Further Reading
- Consumer Financial Protection Bureau — When can I remove private mortgage insurance (PMI)? — The federal Homeowners Protection Act thresholds used here: request at 80% LTV, automatic termination at 78%, and the amortization-midpoint rule, all measured against the original value
- Consumer Financial Protection Bureau — Explore interest rates — US government tool showing the real spread of rates offered by lenders, which is the basis for the point about shopping the rate
- Federal Reserve — Selected Interest Rates (H.15) — Current US benchmark rates, for grounding the rate input in something real rather than a guess
- Freddie Mac — Primary Mortgage Market Survey (PMMS) — The weekly US survey of average 30- and 15-year fixed mortgage rates, and the standard reference for what rate to enter
- eCFR — Regulation Z, Truth in Lending (12 CFR Part 1026) — The US rule governing APR disclosure and the Loan Estimate, which is why a lender’s Loan Estimate rather than any calculator is the binding figure
- Calculator.net — Mortgage Calculator — The most complete competing tool; its published example was reproduced exactly — a $320,000 loan at a solved 6.792% paying $2,084.46, splitting $1,811/$273 in month one and $12/$2,073 in month 360