Mortgage Payment Calculator

Work out your true monthly mortgage cost before you sign. Enter the home price, down payment, interest rate, and loan term, plus property tax, home insurance, HOA dues, and PMI if they apply. This calculator shows the full monthly breakdown (principal and interest, tax, insurance, HOA, PMI), the loan amount and down payment percentage, total interest over the life of the loan, the first-year interest/principal split, and the payoff month.

The short answer: monthly payment = principal and interest from the amortization formula, plus one twelfth of annual property tax and insurance, plus monthly HOA and PMI. For example, a $400,000 home with $80,000 down (20%) at 6.5% for 30 years, $4,800 annual tax, and $1,800 annual insurance: principal and interest $2,022.62, tax $400.00, insurance $150.00, total $2,572.62 per month, with $408,142.36 of total interest over 30 years. Enter your numbers above for the full breakdown.

The mortgage payment formula

Formula: M = P x r(1 + r)^n / ((1 + r)^n – 1), where M is the monthly principal and interest payment, P is the loan amount (home price minus down payment), r is the monthly interest rate (annual rate / 100 / 12), and n is the number of monthly payments (years x 12). Property tax and insurance are added as annual amount / 12. HOA and PMI are added as entered per month.

The formula was checked in Node against the standard amortization equation: a $320,000 loan at 6.5% over 360 months gives $2,022.62, matching the textbook result. A 0% rate is handled as a special case (payment = loan / number of payments) instead of dividing by zero.

Worked example, verified against the tool

$400,000 home price, $80,000 down payment (20%), 6.5% annual rate, 30-year term, $4,800 annual property tax, $1,800 annual insurance, no HOA, no PMI:

Loan amount = 400,000 – 80,000 = $320,000.00. Monthly rate r = 0.065 / 12 = 0.00541667. Payments n = 360. Principal and interest = 320,000 x 0.00541667 x (1.00541667)^360 / ((1.00541667)^360 – 1) = $2,022.62. Property tax = 4,800 / 12 = $400.00. Insurance = 1,800 / 12 = $150.00. Total monthly = 2,022.62 + 400.00 + 150.00 = $2,572.62.

Total interest = 2,022.62 x 360 – 320,000 = $408,142.36. In the first year, $20,694.69 goes to interest and only $3,576.72 reduces the principal, which is why early payments feel like treading water. These are exactly the numbers the calculator above produces; the code was run in Node and every line matched.

15-year vs 30-year: what shorter loan terms really save

The same $320,000 loan at typical rates for each term (verified by running the tool code):

30-year fixed at 6.0%: $1,918.56 per month, $370,682.20 total interest. 20-year fixed at 5.75%: $2,246.67 per month, $219,200.13 total interest. 15-year fixed at 5.5%: $2,614.67 per month, $150,640.07 total interest.

Cutting from 30 years to 15 years raises the payment by about $696 a month but saves roughly $220,000 in interest. Note: an older version of this page printed $2,145 per month for the 20-year row, which was wrong. The corrected $2,246.67 above is what the formula actually produces, and the tool now computes the table values live so they cannot drift again.

A full 15-year worked example with taxes and insurance included: $500,000 home price, $100,000 down payment, $400,000 loan at 3.25% for 15 years, $6,000 annual property tax, $1,200 annual insurance. Principal and interest = $2,810.68 per month. Property tax = 6,000 / 12 = $500.00. Insurance = 1,200 / 12 = $100.00. Total monthly payment = $3,410.68. Total interest over 15 years = $105,922, and the total of all payments (loan plus taxes and insurance) = $613,922. Run the same numbers on a 30-year term in the calculator above and compare: the 15-year loan builds equity dramatically faster because every payment attacks more principal.

Biweekly and bimonthly mortgage payments: pay it off years early

One of the simplest ways to cut your interest bill is to change how often you pay, not how much. A biweekly mortgage payment splits your monthly payment in half and pays that half every two weeks. Because there are 26 biweekly periods in a year, you make the equivalent of 13 monthly payments instead of 12. That one extra payment a year goes straight at the principal, which snowballs.

Verified example: a $250,000 loan at 6% for 30 years. The standard monthly principal and interest is $1,498.88. Pay $749.44 every two weeks instead, and the loan is gone in about 24.5 years instead of 30. Total interest drops from about $289,595 to about $227,565, a saving of roughly $62,000, without raising your annual budget by a dollar.

A quick terminology note, because the two get mixed up: biweekly means every two weeks (26 payments a year). Bimonthly, or semi-monthly, means twice a month (24 payments a year) and does not create the extra payment. If your lender does not offer an automatic biweekly plan, you can get the same effect by making one extra full monthly payment per year and confirming with your lender that it is applied to principal. Ask about setup fees first: some lenders charge for biweekly processing, which eats into the savings.

Fannie Mae conforming loans: the rules behind most US mortgages

Most conventional US mortgages follow standards set by Fannie Mae, the government-sponsored enterprise that buys loans from lenders. Knowing those rules helps you estimate like a lender does. The typical benchmarks: a conforming loan limit of $832,750 for a single-unit home in most counties for 2026 (higher in expensive areas), minimum down payment as low as 3% for first-time buyers, PMI required when the down payment is under 20%, a maximum debt-to-income ratio around 45%, and a minimum credit score near 620.

Worked example under those rules: $400,000 home price, $40,000 down payment (10%), $360,000 loan at 6.75% for 30 years, $4,000 annual property tax, $1,200 annual insurance, PMI at 0.5% of the loan per year ($1,800 / 12 = $150 per month). Principal and interest = $2,334.95. Taxes and insurance = $433.33. PMI = $150.00. Estimated total monthly payment = $2,918.28. Enter these same numbers in the calculator above to reproduce it.

Comparing a credit-union mortgage offer

Credit unions, including large ones like Navy Federal Credit Union (NFCU), are member-owned nonprofits that often offer competitive mortgage rates, low-fee structures, and first-time buyer programs to their members. If you are eligible for membership through military service, a family member, or an employer, a credit-union quote is worth comparing against bank offers.

This page is an independent, free comparison tool and is not affiliated with Navy Federal or any other lender. Use the calculator above to run any credit-union quote through the same math: enter the quoted rate, term, taxes, insurance, and PMI, and you get an apples-to-apples monthly total you can hold next to the lender’s Loan Estimate.

PITI, plus the two costs most calculators hide

Principal: the original loan amount borrowed. Interest: the lender’s charge for the loan, highest in the early years. Taxes: annual property tax divided by 12, usually held in escrow. Insurance: annual homeowners premium divided by 12, also usually escrowed. Together these four are PITI, the number lenders quote.

Two more monthly costs belong in an honest estimate. HOA dues are mandatory in many condos and planned communities and can rival the tax line. PMI (private mortgage insurance) is typically required when the down payment is under 20%, and it protects the lender, not you. This calculator includes both as separate lines instead of leaving you to add them by hand.

Why this beats the other mortgage calculators

Calculator.net and CalculatorSoup both include HOA dues and amortization schedules, which set the bar. The previous version of this page fell short of it: no HOA input, and leaving the loan term blank produced a results box full of $NaN. This rewrite closes both gaps. It adds the HOA line, validates every input with a plain-language error instead of ever showing $NaN, handles a 0% rate without dividing by zero, and adds three readouts the old tool never had: the down payment percentage, the first-year interest/principal split, and the payoff month. Every worked number on this page was generated by the live code and checked by hand.

Frequently asked questions

How is a monthly mortgage payment calculated?
With the amortization formula M = P x r(1 + r)^n / ((1 + r)^n – 1) for principal and interest, then add one twelfth of annual property tax and homeowners insurance, plus monthly HOA dues and PMI. For a $320,000 loan at 6.5% over 30 years, the principal and interest portion is $2,022.62.

What does PITI mean?
Principal, Interest, Taxes, and Insurance: the four components of a standard monthly mortgage payment. Lenders quote PITI when they talk about what you will pay each month, before HOA dues or PMI.

When is PMI required?
Conventional lenders typically require private mortgage insurance when the down payment is under 20% of the home price. It is a monthly cost on top of PITI. Putting 20% down, as in the $80,000 on $400,000 example above, avoids it.

How much interest does a shorter term save?
A lot. On a $320,000 loan, a 15-year term at 5.5% costs $150,640.07 in total interest versus $370,682.20 on a 30-year term at 6.0%, a saving of about $220,000, for roughly $696 more per month. The table above shows all three terms computed by the tool.

Does the calculator include HOA dues?
Yes. Enter monthly HOA dues in the dedicated field and they are added to the total as their own line, so the headline number reflects what actually leaves your account each month.

What happens if I leave a field blank?
The tool tells you exactly what is missing, in plain language, instead of calculating. The old version of this page would print $NaN across the results when the loan term was empty; that bug is fixed.

What is a biweekly mortgage payment, and how much does it save?
You pay half your monthly payment every two weeks, making 26 half-payments a year, equal to 13 full monthly payments. On a $250,000 loan at 6% for 30 years, that pays the loan off in about 24.5 years instead of 30 and saves roughly $62,000 in interest.

Is bimonthly the same as biweekly?
No. Biweekly means every two weeks (26 payments a year), which creates the extra annual payment. Bimonthly, or semi-monthly, means twice a month (24 payments a year) and gives no extra payment. Only the biweekly pattern shortens the loan.

Should I choose a 15-year or a 30-year mortgage?
A 15-year loan costs more per month but far less in total interest: on a $320,000 loan the 15-year option saves about $220,000 versus the 30-year. Choose the 15-year if the higher payment fits comfortably in your budget; choose the 30-year if you need payment flexibility and plan to invest the difference or pay extra voluntarily.

What is a Fannie Mae conforming loan?
A conventional mortgage that meets Fannie Mae’s purchase standards, which most US lenders follow. Typical benchmarks: loan at or under the conforming limit ($832,750 for most counties in 2026), down payment as low as 3% for first-time buyers, PMI under 20% down, debt-to-income ratio around 45% or less, and credit score near 620 or higher.

Can I use this calculator for a credit-union mortgage?
Yes. Enter the credit union’s quoted rate, term, taxes, insurance, HOA, and PMI, and the calculator gives you the same full breakdown for an apples-to-apples comparison. This tool is independent and not affiliated with any credit union, including Navy Federal.

When does PMI go away?
On a conventional loan you can usually request cancellation once your loan balance falls to 80% of the home’s value, and the lender must drop it automatically at 78%. PMI typically costs 0.3% to 1.5% of the loan amount per year, so reaching 20% equity is worth pursuing.

What is the difference between APR and the interest rate?
The interest rate is what the lender charges on the loan balance. The APR folds in lender fees and closing costs to reflect the true yearly cost of borrowing, so it is usually slightly higher. Use the interest rate in this calculator and compare APRs when shopping between lenders.

Amortization schedule and extra payments

Every calculation now includes a year-by-year amortization schedule: interest paid, principal paid, and remaining balance for each year of the loan. On a $320,000 loan at 6.5% over 30 years, the first year puts about $20,695 toward interest and only about $3,577 toward principal. That is normal: early payments are mostly interest because the balance is at its largest.

Enter an extra monthly payment to see the payoff analysis. Paying $500 extra per month on that same loan pays it off in 18 years instead of 30 and saves about $185,552 in interest. The schedule rebuilds itself to reflect the extra payments, so you can watch the balance fall year by year.

DTI affordability check

Enter your gross monthly income and other monthly debts for a debt-to-income check. The calculator computes your front-end ratio (housing costs divided by income) and back-end ratio (all monthly debts divided by income), then scores them against conventional loan benchmarks: about 28% front-end and 36% back-end, with some lenders approving up to 45% back-end for borrowers with strong credit and reserves. It also shows the maximum housing payment your income supports at the 28% guideline. For example, $10,000 monthly income with $800 in other debts and a $2,572.62 housing payment gives 25.7% front-end and 33.7% back-end: within the standard benchmarks.