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. Before you commit, check what you can actually afford with our affordability ratio calculator.

Quick Answer

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.

Each monthly payment splits into an interest part and a principal part on a fixed schedule. Our amortization schedule calculator breaks down that split month by month for any loan.

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):

Average rates as of October 2026. 30-year and 15-year figures: Freddie Mac Primary Mortgage Market Survey, week ending October 15, 2026. 5/1 ARM figure: Bankrate national average, October 2026.

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 every value in the table was recomputed from that same formula, so the table and the calculator cannot drift apart.

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. If rates fall after you buy, our cost to refinance calculator shows whether refinancing into a cheaper or shorter loan pays off.

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. If you itemize deductions, mortgage interest may be deductible under IRS rules. 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. PMI usually falls off once you reach 20% equity, and the year-by-year schedule above shows your balance walking toward that line. 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.

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. For a closer look at how lenders score your debts, try our debt-to-income ratio calculator.

What sets your mortgage rate, and how discount points work

Your rate is priced from your credit score, your down payment size, the loan type you choose, and the market on the day you lock. A higher credit score and a bigger down payment usually earn a lower rate, because both lower the lender’s risk. Discount points let you buy the rate down: one point costs 1% of the loan amount and typically lowers the rate by about 0.25%, so compare the upfront cost against the monthly saving to find your breakeven point.

Lenders sort borrowers into pricing tiers, and the gaps are real money. A borrower with a 760 credit score can pay noticeably less than one at 680 on the same loan, and putting 20% down instead of 5% removes PMI and often improves the rate itself. The loan type matters too: a 30-year fixed rate is usually higher than a 15-year fixed, and a 5/1 ARM starts lower than either fixed option but can adjust after the first five years. The market sets the baseline for everyone: the rate table above uses Freddie Mac’s weekly survey averages.

Points are prepaid interest, and the breakeven math decides whether they are worth it. On the $320,000 loan in the worked example, one point costs $3,200. If that point buys the rate down from 6.5% to 6.25%, the principal-and-interest payment falls from $2,022.62 to $1,970.30, a saving of $52.32 a month. Divide $3,200 by $52.32 and the breakeven is about 61 months: stay past five years and the point pays for itself, but sell or refinance sooner and it was a loss. Run both rates through the calculator above to check the exact breakeven for your numbers.

If the budget is tight, there is a cheaper shortcut: instead of paying points, the biweekly approach in the section above cuts interest with no upfront fee. And remember the rate is only part of the price. Lender fees folded into the APR, covered in the questions below, are what separate two quotes that show the same rate.

Frequently asked questions