Mortgage Payment Formula: Calculate Each PITI Component (2026)
A mortgage payment has four core components: principal, interest, taxes, and insurance, abbreviated PITI — and each one has its own formula. On a typical 2026 purchase — a $405,300 home with 10% down, financed at 6.5% over 30 years — those four parts combine to roughly $3,032 per month, with principal and interest alone making up $2,306 of it. Enter your own numbers in the Mortgage Calculator to see the split for your loan.
The "principal and interest" number a lender advertises is rarely the number that hits your account. The amortization formula produces only the P&I figure; property taxes, homeowners insurance, and PMI are added separately and can lift the real payment by hundreds of dollars a month. This guide shows the exact calculation behind each component so you can rebuild — and sanity-check — any quote yourself.
This article focuses on the formula and step-by-step math for each component. For a plain-language tour of what each part pays for and how to avoid escrow surprises, see the companion What's Really In Your Mortgage Payment? The Complete Breakdown.
The Four Components of a Mortgage Payment (PITI)
PITI stands for Principal, Interest, Taxes, and Insurance. Every monthly housing payment held in an escrow account combines these four parts into a single charge. A fifth and sixth charge — private mortgage insurance (PMI) and homeowners association (HOA) dues — apply only in specific situations.
Here is how each component behaves over the life of the loan:
| Component | What it pays for | 2026 sample (monthly) | Changes over time? |
|---|---|---|---|
| Principal | Repays the amount you borrowed | $330 (month 1) | Rises every month |
| Interest | The lender's charge for the loan | $1,976 (month 1) | Falls every month |
| Taxes | County/local property tax | $372 | Resets yearly |
| Insurance | Homeowners (hazard) insurance | $202 | Resets yearly |
| PMI | Lender protection for <20% down | $152 | Drops off near 20% equity |
| HOA | Community/condo association dues | Varies ($0–$700+) | Set by the HOA |
The sample above uses a $364,770 loan (10% down on a $405,300 home) at 6.5% for 30 years. Principal and interest together are fixed at $2,306; what shifts month to month is how that $2,306 splits between the two. Try the Mortgage Calculator to generate the same table for your price and rate.
Important
"PITI" is the number lenders use to qualify you, not the "principal and interest" figure in an ad. When a loan officer says your payment is $2,306, ask whether that includes taxes and insurance. It usually does not.
Component 1: Principal — The Money You Actually Borrowed
Principal is the portion of each payment that reduces your loan balance. Borrow $364,770 and every principal dollar you pay shrinks that balance toward zero. In the first month of our sample loan, only $330 of the $2,306 payment goes to principal. By year 15, that share more than doubles.
The amortization formula sets the fixed principal-and-interest payment:
M = P × [ r(1 + r)ⁿ ] / [ (1 + r)ⁿ − 1 ]
Where:
- M = monthly principal + interest payment
- P = principal (loan amount) = $364,770
- r = monthly interest rate = 6.5% ÷ 12 = 0.0054167
- n = number of payments = 30 × 12 = 360
Plugging those in returns $2,305.59, which we round to $2,306. The formula is identical at every U.S. lender, so two banks quoting the same rate and term will quote the same payment.
Tip
Paying just $100 extra toward principal each month on this loan cuts about 3.4 years off the term and roughly $63,000 in total interest. Principal is the only component you can attack directly.
Component 2: Interest — The Cost of Borrowing
Interest is the fee the lender charges for lending you the principal. It is calculated on the remaining balance each month, which is why it starts high and falls over time. Month one interest on a $364,770 balance at 6.5% is the balance times the monthly rate: $364,770 × 0.0054167 = $1,976.
That single figure is why early payments feel like they barely move the needle. In month one, 86% of your $2,306 principal-and-interest payment is pure interest. Principal does not overtake interest until around month 233 — roughly year 19 of a 30-year loan.
How the Principal/Interest Split Shifts
| Payment month | Interest portion | Principal portion | Balance after |
|---|---|---|---|
| 1 | $1,976 | $330 | $364,440 |
| 60 (year 5) | $1,852 | $454 | $341,465 |
| 180 (year 15) | $1,438 | $867 | $264,674 |
| 360 (final) | $12 | $2,293 | $0 |
The principal-and-interest payment stays $2,306 across all 360 months; only the internal split moves. According to Freddie Mac's Primary Mortgage Market Survey, the 30-year fixed rate averaged 6.53% as of late May 2026, so a 6.5% example reflects current borrowing costs closely. Compare loan structures with the FHA Loan Calculator if you are putting less than 10% down.
Warning
A lower rate changes the interest component dramatically. Dropping from 6.5% to 5.5% on this loan cuts the monthly payment by about $234 and saves roughly $84,000 in interest over 30 years. Always price the rate, not just the payment.
Component 3: Taxes — Property Tax Held in Escrow
Property taxes are levied by your county or municipality, based on your home's assessed value. Most lenders collect 1/12 of the annual bill with each payment and hold it in an escrow account, then pay the county on your behalf. This is the "T" in PITI.
The national average effective property tax rate is about 1.1% of home value, per the Tax Foundation's property tax data. On a $405,300 home, that is $4,458 per year, or $372 per month. But the spread between states is enormous.
Property Tax by State (Effective Rate Examples)
| State | Effective rate | Annual on $405,300 | Monthly escrow |
|---|---|---|---|
| Hawaii | 0.27% | $1,094 | $91 |
| National average | 1.10% | $4,458 | $372 |
| Texas | 1.58% | $6,404 | $534 |
| Illinois | 2.07% | $8,390 | $699 |
| New Jersey | 2.23% | $9,038 | $753 |
Rates above are drawn from Tax Foundation state rankings; multiply your home value by the rate and divide by 12 to get the monthly escrow amount. Estimate yours precisely with the Property Tax Calculator.
Tip
If your escrow comes up short because the county reassessed your home upward, your lender raises your monthly payment to refill it — often with a one-time "escrow shortage" catch-up charge on top. Budget for a 5–10% annual creep in this component.
Component 4: Insurance — Homeowners (Hazard) Insurance
Homeowners insurance protects the physical home against fire, storms, theft, and liability claims. Lenders require it for the life of the loan and usually escrow it like property taxes. This is the "I" in PITI.
The U.S. average premium is about $2,424 per year for $300,000 in dwelling coverage, according to NerdWallet's 2026 rate analysis, which works out to $202 per month. Premiums have climbed fast: Bankrate reports double-digit annual increases in recent years, with disaster-prone states running far above the average.
Insurance is the most location-sensitive component. A coastal Florida home or a wildfire-zone California property can carry premiums three to five times the national figure. Get a current figure with the Home Insurance Quote Calculator before you finalize a budget.
The Fifth Component: PMI (When You Put Down Less Than 20%)
Private mortgage insurance protects the lender — not you — when your down payment is under 20% of the home price. It is added to the monthly payment until you reach about 20% equity, then it drops off.
PMI typically runs 0.46% to 1.5% of the loan amount per year, per Bankrate's PMI overview. On our $364,770 loan at a mid-range 0.5%, that is $1,824 a year, or $152 per month. At a higher 1.0% rate, the same loan would carry $304 per month in PMI.
Warning
PMI is the one component you can legally cancel. Under the Homeowners Protection Act, your servicer must automatically terminate PMI once your balance reaches 78% of the original home value, and you can request removal at 80%. Waiting can cost you over $1,800 a year you no longer owe.
Putting It All Together: A Full Payment Breakdown
Here is the complete first-month payment for our sample loan, with each component's share of the total. This is the table to screenshot before you talk to a lender.
| Component | Monthly amount | Share of payment |
|---|---|---|
| Principal | $330 | 10.9% |
| Interest | $1,976 | 65.2% |
| Property tax | $372 | 12.3% |
| Homeowners insurance | $202 | 6.7% |
| PMI | $152 | 5.0% |
| Total PITI + PMI | $3,032 | 100% |
Principal and interest together ($2,306) make up 76.1% of the payment; the escrowed taxes, insurance, and PMI add the remaining $726. That $726 is precisely the "hidden" portion most first-time buyers overlook.
Same Home, 20% Down (No PMI)
Putting $81,060 down (20%) drops the loan to $324,240 and removes PMI entirely:
| Component | Monthly amount |
|---|---|
| Principal + interest | $2,049 |
| Property tax | $372 |
| Homeowners insurance | $202 |
| Total PITI | $2,623 |
The larger down payment cuts the monthly payment from $3,032 to $2,623 — a $409 difference, of which $152 is the eliminated PMI and $257 is the lower principal-and-interest on a smaller loan. Lenders also weigh this full PITI figure against your income; check whether yours fits with the Debt-to-Income Calculator.
Tip
Closing costs are a separate one-time charge, not part of the monthly payment, but they catch buyers off guard too. Estimate them with the Closing Cost Calculator and add 2–5% of the loan amount to your cash-to-close budget.
How to Calculate Each Component Yourself
You can rebuild any mortgage payment with five inputs and four short steps:
- Principal and interest: Apply the amortization formula M = P × [r(1+r)ⁿ] / [(1+r)ⁿ − 1] using your loan amount, monthly rate, and 360 payments.
- Property tax: Multiply home value by your local effective rate, then divide by 12.
- Insurance: Take your annual homeowners premium and divide by 12.
- PMI (if under 20% down): Multiply the loan amount by your PMI rate (0.46%–1.5%), then divide by 12.
Add the four results and you have your true monthly housing cost. The Mortgage Calculator automates every step, but doing it once by hand is the best way to spot a lender's lowball "P&I only" quote. For a deeper walkthrough of the formula's variables, see How to Calculate Your Mortgage Payment, and to weigh fixed versus adjustable and 15- versus 30-year structures, read our Mortgage Types Comparison.
Frequently Asked Questions
What are the components of a mortgage payment?
A mortgage payment has four core components — principal, interest, taxes, and insurance (PITI) — plus PMI when your down payment is under 20% and HOA dues if your community charges them. On our $405,300 sample home, those parts total about $3,032 per month, with principal and interest making up $2,306 of it.
What is the mortgage payment formula?
The mortgage payment formula for principal and interest is M = P × [r(1+r)ⁿ] / [(1+r)ⁿ − 1], where P is the loan amount, r is the monthly interest rate, and n is the total number of payments. For a $364,770 loan at 6.5% over 30 years, it returns $2,306, to which you add monthly taxes, insurance, and any PMI.
What is the mortgage payment calculation formula step by step?
The full calculation has four steps: compute principal and interest with the amortization formula, add the monthly property tax (home value × tax rate ÷ 12), add the monthly homeowners insurance (annual premium ÷ 12), and add monthly PMI if applicable (loan × PMI rate ÷ 12). For our sample, that is $2,306 + $372 + $202 + $152 = $3,032.
Does the mortgage payment calculator formula include taxes and insurance?
Our Mortgage Calculator formula includes principal, interest, property tax, homeowners insurance, and optional PMI, producing the full PITI figure lenders use to qualify you. Many lender ads quote only principal and interest, which on this sample loan understates the true payment by about $726 a month.
How much of my mortgage payment goes to interest?
In the first month of a 30-year loan, interest is the largest component — about $1,976 of the $2,306 principal-and-interest payment on our $364,770 example, or 86% of it. That share falls every month as the balance shrinks, and principal does not overtake interest until around year 19 of the loan.
Can I lower the components of my mortgage payment?
Yes — each component responds to a different lever. A lower interest rate cuts the interest portion, a 20% down payment removes PMI (worth $152/month here), extra principal payments shorten the loan, and shopping insurers or appealing a tax assessment trims the escrowed taxes and insurance.
Is PMI a permanent part of the mortgage payment?
No. PMI drops off automatically when your loan balance reaches 78% of the original home value, and you can request removal at 80% under the Homeowners Protection Act. On our example, that eliminates about $152 per month, or over $1,800 a year.
Related Articles
- How to Calculate Your Mortgage Payment — The step-by-step math of the amortization formula behind the principal and interest component.
- Mortgage Types Comparison — Fixed vs. adjustable and 15- vs. 30-year loans, and how each changes your monthly components.
Related Calculators
- Mortgage Calculator — Builds the full PITI payment from your price, rate, and down payment.
- Property Tax Calculator — Estimates the monthly tax escrow for your state and home value.
- Home Insurance Quote Calculator — Estimates the homeowners insurance component for your location.
- Closing Cost Calculator — Estimates the one-time costs that sit outside the monthly payment.
- Debt-to-Income Calculator — Checks whether your full PITI fits the ratios lenders require.
This article provides general information for educational purposes. Property tax rates, insurance premiums, and mortgage rates vary by location and change over time. Consult a licensed mortgage professional for personalized guidance.
This article is provided for informational and educational purposes only. Content should not be considered professional financial, medical, legal, or other advice. Always consult a qualified professional before making important decisions. UseCalcPro is not responsible for any actions taken based on the information in this article.
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