Most mortgage calculators show you one number: principal and interest. That number is not your payment.
This one calculates your full PITI – the four components that actually leave your bank account each month:
- Principal: the part that reduces what you owe
- Interest: the cost of borrowing
- Taxes: your property tax, spread monthly into escrow
- Insurance: your homeowners premium, plus PMI if you put less than 20% down
On a typical loan, principal and interest is only about 79% of the real payment. The other 21% catches people out – it’s why a “$2,000 a month” mortgage turns into a $2,550 reality.
Table of Contents
How to Use Mortgage Calculator?
Seven inputs, results updating as you type:
- Loan Amount — what you’re borrowing, not the home price. Subtract your down payment first.
- Down Payment — cash you’re putting in up front.
- Interest Rate — your quoted rate, not the APR.
- Loan Term — 30 years is standard; 15 is common for refinances.
- Property Tax — your annual bill, divided by 12 for the monthly figure.
- Home Insurance — your annual premium.
- PMI — private mortgage insurance, annual. Leave at zero if you’re putting 20% or more down.
You’ll get eight outputs: your total monthly payment, each PITI component broken out, total interest over the life of the loan, total of all payments, and your payoff date.
Mortgage Calculator Worked Example
A $400,000 home with 20% down ($80,000), a $320,000 loan at 6.5% for 30 years, with $4,800/year in property tax and $1,500/year in insurance:
| Principal & Interest | $2,022.62 |
| Property Tax | $400.00 |
| Home Insurance | $125.00 |
| PMI | $0.00 |
| Total Monthly Payment | $2,547.62 |
| Total interest over 30 years | $408,142.36 |
| Payoff date | 30 years from your first payment |
You’ll pay $408,142 in interest to borrow $320,000. That’s more than the loan itself – which is the single most under-appreciated fact about a 30-year mortgage.
Where Your Payment Actually Goes?
| Component | Monthly | Share |
|---|---|---|
| Principal & Interest | $2,022.62 | 79.4% |
| Property Tax | $400.00 | 15.7% |
| Home Insurance | $125.00 | 4.9% |
Two things worth noticing. Property tax is a bigger slice than insurance on most loans, and it doesn’t go down when you pay the mortgage off – it usually rises with your home’s assessed value. People budget the P&I dropping away in year 30 and forget the tax stays forever.
Also: in the early years, almost all of that $2,022 is interest. In month one, you pay $1,733.33 in interest and only $289.28 toward principal. The split doesn’t flip until month 233 – year 19.4. You will have made 19 years of payments before more than half of any payment goes toward owning the house.
PMI: What It Costs and When It Ends
Put less than 20% down and your lender requires private mortgage insurance. It protects them, not you. Typical cost is 0.5%–1% of the loan per year.
At 0.75%, a $360,000 loan costs $225/month in PMI – $2,700 a year for insurance that pays you nothing.
The good news: it ends. Once you reach 20% equity (80% loan-to-value), you can request cancellation. On a $360,000 loan against a $400,000 home, amortisation alone gets you there in about 95 months – just under 8 years. You can reach it sooner by making extra principal payments, or immediately if your home appreciates and you get a new appraisal.
Worth asking your lender two questions at closing: is PMI cancellation automatic at 78% LTV, and are there extra principal payments allowed without penalty?
How Much Does Your Down Payment Change Things?
Same $400,000 home, 6.5%, 30 years, same tax and insurance:
| Down | Loan | P&I/mo | PMI/mo | Total/mo | Total Interest |
|---|---|---|---|---|---|
| 3.5% | $386,000 | $2,439.78 | $241.25 | $3,206.03 | $492,322 |
| 5% | $380,000 | $2,401.86 | $237.50 | $3,164.36 | $484,669 |
| 10% | $360,000 | $2,275.44 | $225.00 | $3,025.44 | $459,160 |
| 15% | $340,000 | $2,149.03 | $212.50 | $2,886.53 | $433,651 |
| 20% | $320,000 | $2,022.62 | $0.00 | $2,547.62 | $408,142 |
| 25% | $300,000 | $1,896.20 | $0.00 | $2,421.20 | $382,633 |
The 15% → 20% row is the important one. Putting down an extra $20,000 drops your payment by $338.91 a month – because you shrink the loan and eliminate PMI at the same time. That $20,000 pays itself back in payment savings in about 4.9 years, and everything after that is pure gain.
Going from 10% to 20% down saves $477.82 a month.
The 20% threshold is a genuine cliff, not a gradual slope. If you’re at 18% and can stretch, stretch.
15-Year vs 30-Year
Same $320,000 at 6.5%:
| Years | Monthly P&I | Total Interest |
|---|---|---|
| 30-year | $2,022.62 | $408,142 |
| 15-year | $2,787.54 | $181,758 |
The 15-year costs $764.93 more per month but saves $226,385 in interest.
Whether that’s worth it depends entirely on what else you’d do with $765 a month. Invested at any reasonable return, it beats the 6.5% you’re saving. But the 15-year forces the discipline, and it halves the time you’re in debt. Neither answer is wrong.
A middle path most people miss: take the 30-year for the lower required payment, then pay it like a 15-year. You get the savings when you can afford them and the flexibility when you can’t.
What Your Rate Is Actually Worth?
On the same $320,000 loan over 30 years:
| Rate | P&I/mo | Full PITI/mo | vs 6.5% | Total Interest |
|---|---|---|---|---|
| 5.5% | $1,816.92 | $2,341.92 | −$205.69 | $334,093 |
| 6.0% | $1,918.56 | $2,443.56 | −$104.06 | $370,682 |
| 6.5% | $2,022.62 | $2,547.62 | — | $408,142 |
| 7.0% | $2,128.97 | $2,653.97 | +$106.35 | $446,428 |
| 7.5% | $2,237.49 | $2,762.49 | +$214.87 | $485,495 |
| 8.0% | $2,348.05 | $2,873.05 | +$325.43 | $525,297 |
A single point of rate costs $205.69 a month and $74,049 over the life of the loan. Even half a point is $104 a month.
This is why rate shopping is worth more than almost anything else you can do. Getting three Loan Estimates from different lenders takes an afternoon and routinely surfaces a quarter to half a point of spread – that’s $50–$105 a month for an hour of work.
Should you buy points?
One discount point costs 1% of the loan – $3,200 on this loan– and typically buys about 0.25% off your rate, worth $52.32 a month.
Break-even is 61 months, or 5.1 years. If you’ll stay in the home longer, points pay. If you might move inside five years, they’re a bad trade – you’ll have paid $3,200 to save less than that back.
Compare offers using APR rather than rate, since APR folds the point cost in. That’s exactly what our APR calculator does.
Understanding Escrow
If your lender collects tax and insurance monthly, they hold it in an escrow account and pay the bills for you. Three consequences worth knowing:
Your payment can change mid-year. When your county reassesses property values or your insurer raises premiums, your escrow comes up short, and the lender recalculates. A $600/year tax increase adds $50 to every monthly payment — with no notice beyond a letter most people skim.
Lenders require a cushion. Most keep two months of escrow expenses on hand, so your account holds more than the annual bill at any given time.
You can sometimes cancel it. Once you pass 80% loan-to-value, some lenders will let you pay tax and insurance directly. You keep the float, but you also take on the risk of a missed payment triggering force-placed insurance, which costs far more.
This calculator shows the escrow components separately for exactly this reason — so you can see which part of your payment is fixed and which part will move.
What This Calculator Doesn’t Include
Be aware of these before you budget:
- HOA fees: can be $100–$800/month in some developments. This is the most common omission, and it’s a real payment.
- Closing costs: typically 2%–5% of the loan, paid at closing.
- Mortgage insurance on FHA/VA loans: different structure from conventional PMI.
- Maintenance: a rough rule is 1% of home value per year.
- Escrow shortages: when taxes or insurance rise, your payment rises mid-year.
If your property has an HOA, add it manually to the total this calculator gives you.
Can You Actually Afford This Payment?
Lenders use the 28/36 rule: housing costs shouldn’t exceed 28% of gross monthly income, and total debt shouldn’t exceed 36%.
For the $2,547.62 payment above, you’d need roughly $9,099/month gross – about $109,000 a year – to stay inside the 28% line.
Note what that means. A $400,000 home requires a six-figure income under conventional lending standards. If that surprises you, run our house affordability calculator backwards from your actual income before you fall in love with a listing.
Three Ways to Lower Your Payment
- Buy down the rate with points. One point (1% of the loan) typically lowers your rate by about 0.25%. It only pays off if you stay past the break-even – use our APR calculator to compare offers properly.
- Put 20% down. As the table shows, this is the highest-leverage move available.
- Extend the term. A 30-year instead of a 15-year cuts the payment sharply at the cost of roughly double the interest.
What doesn’t help: shopping only the monthly payment. Two loans with identical payments can differ by tens of thousands in total cost. Compare APR, not payment.
Frequently Asked Questions
What is PITI?
Principal, Interest, Taxes and Insurance – the four parts of a full mortgage payment. Lenders qualify you on PITI, not on principal and interest alone.
Why is my payment higher than the calculator says?
Usually HOA fees, an escrow shortage after a tax reassessment, or a rate that changed between pre-approval and closing.
Does putting 20% down always make sense?
Not always. If the cash would earn more invested than your mortgage rate costs you, a smaller down payment can be mathematically better – but you’ll pay PMI until you hit 20% equity.
How much income do I need for a $300,000 mortgage?
About $97,000–$101,000 a year at 6.5%, assuming roughly 1%–1.2% of home value in annual property tax and $1,500–$1,800 in insurance. That puts PITI near $2,270–$2,350, which is the 28% ceiling on that income. Your other debts push the requirement higher.
Is it better to pay extra principal or invest?
Compare your mortgage rate against your expected after-tax investment return. Above roughly 6%, paying down the mortgage is competitive with most low-risk investments.
Does this calculator include closing costs?
No. Add 2%–5% of the loan amount for closing costs, and add HOA fees separately if your property has them.