Mortgage Calculator
The Mortgage Calculator estimates your monthly principal and interest payment based on home price, down payment, interest rate, and loan term, with optional fields for property tax, insurance, and HOA dues. If you enter a 0% interest rate, the calculator switches to simple division (loan amount ÷ number of months) since the standard amortization formula would otherwise divide by zero. The tool floors the loan amount at $0 if your down payment ever exceeds the home price, and it computes principal & interest only — property tax and insurance are added on top as flat monthly figures rather than recalculated as your home's assessed value changes over time. Because it applies one constant rate across the full term, treat the result as valid only for the fixed-rate period of an ARM, not its entire life.
How This Tool Works
Enter your home price, down payment, interest rate, and loan term. Optionally add annual property tax, insurance, and monthly HOA dues for a complete monthly payment estimate.
Formula & Method
Monthly principal & interest = 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 number of payments.
Example Calculation
A $350,000 home with a $70,000 down payment leaves a $280,000 loan amount. Step 1: convert the annual rate to a monthly rate — 6.5% ÷ 12 = 0.541667% (0.00541667 as a decimal). Step 2: raise (1 + monthly rate) to the power of the total number of payments — (1.00541667)^360 ≈ 6.99180. Step 3: apply the amortization formula — M = 280,000 × 0.00541667 × 6.99180 ÷ (6.99180 − 1) = $1,769.79/month, which rounds to about $1,770/month in principal & interest. Step 4: multiply by 360 payments for total paid — $1,769.79 × 360 = $637,124.57. Step 5: subtract the loan amount for total interest — $637,124.57 − $280,000 = $357,124.57, meaning you'd pay more in interest than the original loan amount over the full 30 years.
About the Mortgage Calculator
A mortgage payment is usually the largest recurring bill in a household budget, and the number a lender quotes in a headline rate is rarely the number that leaves your bank account each month. This calculator closes that gap. You enter the home price, the cash you are putting down, the interest rate, and the loan term, and it works out the monthly principal and interest using the standard fixed-rate amortization formula. If you also fill in annual property tax, annual homeowners insurance, and monthly HOA dues, it adds those to give a realistic all-in monthly figure.
The tool is most useful early in the process, before you have a pre-approval letter or a loan estimate in hand. Changing one input at a time shows how sensitive the payment is to each decision: a quarter-point change in rate, an extra $20,000 down, or a 15-year term instead of 30. Because the formula holds the rate constant for the entire term, it is a fair model of a fixed-rate loan and of the initial fixed period of an adjustable-rate loan, but not of what happens after an adjustment.
The results panel also reports total interest and total cost over the full term, which is where many buyers get their first real surprise. On a 30-year loan at a typical rate, total interest often rivals or exceeds the amount borrowed. Seeing that figure next to the monthly payment helps you weigh a lower payment against a much higher lifetime cost, and decide whether a shorter term, a larger down payment, or a cheaper house better fits your finances.
When to Use It
Setting a realistic house-hunting budget
A couple earning a combined salary wants to know what price range to browse before talking to a lender. They enter a few candidate prices with their planned down payment, a current-looking rate, and local tax and insurance estimates, then compare the total monthly payment with what they can comfortably spend each month after savings and other debts.
Comparing a 30-year loan with a 15-year loan
A buyer with stable income wonders if a 15-year term is worth the higher payment. They run the same home price and rate twice, once at 30 years and once at 15, and compare the monthly payment against the total interest saved, then decide whether the extra cash flow each month is affordable and worth the lifetime savings.
Seeing how a bigger down payment changes things
A first-time buyer has $40,000 saved but could borrow from family to put down more. By trying several down payment amounts, they see how each additional $10,000 reduces the loan, the monthly principal and interest, and total interest, which helps them decide how much cash to commit and how much to keep as an emergency reserve.
Checking whether a listing's HOA and taxes are a dealbreaker
Two similar condos are listed at the same price, but one carries a high monthly HOA fee and the other sits in a higher-tax area. Entering each property's dues and annual tax shows the true monthly cost of both, so the buyer can compare total ownership cost rather than just the sticker price.
How to Use It, Step by Step
- Enter the Home price in dollars. Use the list price for a first look, or your expected offer price if you plan to bid below or above asking.
- Type your Down payment in dollars, not as a percentage. If you are putting 20 percent down on a $425,000 home, enter 85000. The field starts at 70000, so replace it with your own figure.
- Enter the Interest rate as an annual percentage, such as 6.25. Use a rate quoted for your credit profile and loan type, since lenders publish different rates for different borrowers and points.
- Choose the Loan term from the dropdown: 30, 20, 15, or 10 years. Thirty years is preselected. If you plan to refinance later, model the term you would actually carry today.
- Optionally add Annual property tax in dollars. You can find this on the listing, the county assessor's website, or the seller's most recent tax bill. Remember that the bill may be reassessed after a sale.
- Optionally add Annual home insurance in dollars. Ask an insurance agent for a quote on the specific property, as premiums vary a lot by location, roof age, and coverage amount.
- Optionally add Monthly HOA dues in dollars, using the figure on the listing or HOA documents. Leave all three optional fields at 0 to see principal and interest alone.
- Press the calculate button, then read the Principal and interest line, the Total estimated monthly payment, and the total interest and total cost lines. Change one input at a time to see what moves the result.
Understanding Your Results
The Loan amount line is the home price minus your down payment, never below zero. The Principal and interest line is the fixed payment that retires that loan by the end of the term; it stays the same every month on a fixed-rate loan. The line labeled Monthly tax, insurance and HOA combines your optional entries, with annual figures divided by 12. The Total estimated monthly payment is the sum of principal and interest plus those extras, and it is the number to compare with your budget.
Total interest over loan term is the sum of all principal and interest payments minus the loan amount. Total cost of loan is the sum of all principal and interest payments only. It does not include your down payment, taxes, insurance, HOA dues, closing costs, or maintenance, so do not read it as the all-in price of owning the house. A quick sanity check: at roughly 6 to 7 percent over 30 years, total interest typically comes out above the amount borrowed; at a 15-year term it is far lower.
Next, test the result against a few rules of thumb. Lenders often look at the share of gross monthly income that goes to housing and to all debts combined, so compare your total monthly payment with your income. Then stress-test: raise the rate by half a point, raise tax and insurance by 10 percent, and see whether the payment still fits. If the margin disappears, the house probably costs more than you can comfortably carry.
More Worked Examples
Standard 30-year purchase with 20 percent down
Scenario: A $425,000 home with $85,000 down, a 6.25 percent rate, a 30-year term, $5,100 annual property tax, $1,500 annual insurance, and no HOA.
The loan amount is $425,000 minus $85,000, or $340,000. The calculator returns principal and interest of $2,093.44 per month. Tax of $5,100 divided by 12 is $425 and insurance of $1,500 divided by 12 is $125, so extras total $550.00, giving a total estimated monthly payment of $2,643.44. Total interest over 30 years is $413,637.85, which exceeds the $340,000 borrowed, and total cost of the loan is $753,637.85.
15-year loan on a smaller condo with HOA dues
Scenario: A $275,000 condo with $55,000 down, a 5.75 percent rate, a 15-year term, $3,300 annual tax, $1,200 annual insurance, and $85 monthly HOA dues.
The loan amount is $220,000. Principal and interest comes to $1,826.90 per month. Monthly extras are $275 for tax, $100 for insurance, and $85 for HOA, totaling $460.00, so the total estimated monthly payment is $2,286.90. Total interest over the 15 years is $108,842.39, and total cost of the loan is $328,842.39. Notice that interest here is about half the amount borrowed, much lower than in a 30-year loan.
Comparing 30-year and 15-year terms at 7 percent
Scenario: A $520,000 home with $52,000 (10 percent) down at 7 percent, run once with a 30-year term and once with a 15-year term, leaving tax, insurance, and HOA at 0.
Both runs borrow $468,000. The 30-year term gives principal and interest of $3,113.62 per month with total interest of $652,901.64. The 15-year term gives $4,206.52 per month with total interest of $289,172.94. The shorter term costs $1,092.90 more each month but saves $363,728.70 in interest. Because the down payment is under 20 percent, a lender would likely also require mortgage insurance, which this tool does not model.
Tips for Better Results
- Run each scenario at two or three interest rates, such as your quoted rate and a rate half a point higher, so you know how much room you have if the rate moves before you lock.
- Ask the listing agent or check the county assessor for the real property tax figure, and keep in mind that in many areas the tax bill is recalculated based on the new sale price after you buy.
- If your down payment is below 20 percent of the price, add an estimate for private mortgage insurance into the annual insurance field so the total monthly payment is not understated.
- Compare the total monthly payment with your take-home pay, not just gross income, and leave room for maintenance, which many owners budget as a percentage of the home's value each year.
- Try the 20-year and 10-year terms as well as 15 and 30. A 20-year loan often gives a payment close to a 30-year one while cutting interest substantially, depending on the rate difference the lender offers.
- Use the same inputs for every house you compare. When only the price, tax, and HOA change, differences in the total monthly payment become obvious and easy to rank.
Common Mistakes to Avoid
- Entering the down payment as a percentage. The field expects dollars, so typing 20 means a $20 down payment. Multiply the price by your percentage first and enter that dollar amount.
- Reading principal and interest as the full payment. Taxes, insurance, and HOA dues can add hundreds of dollars a month, so fill in the optional fields before comparing to your budget.
- Forgetting private mortgage insurance on low down payments. The tool does not calculate it, so if you put down less than 20 percent, add an estimate yourself or ask a lender for a quote.
- Treating the quoted rate as the final rate. Your actual rate depends on your credit, the loan type, and whether you pay points, so use a rate from a recent lender estimate rather than an advertised one.
- Using a 30-year payment as proof you can afford a 15-year loan. Always rerun the calculation at the term you actually plan to take, since the monthly amount changes substantially with term.
Assumptions and Limits
- The calculator assumes a fixed interest rate and equal monthly payments for the whole term. For an adjustable-rate mortgage, the result is accurate only for the initial fixed period and will change once the rate adjusts.
- Property tax, insurance, and HOA dues are treated as flat monthly amounts. In reality they typically rise over time, and escrow accounts can be adjusted by your servicer each year.
- Closing costs, origination fees, discount points, mortgage insurance, and prepayment effects are not included. Dollar results are rounded to cents for display, so totals can differ from the displayed payment multiplied by the number of months by a small amount.
- This is an estimate for planning, not a loan offer. Your lender's loan estimate document and a licensed mortgage professional or housing counselor should be your source for binding figures.
Key Terms
- Principal
- The amount you actually borrowed. Each payment reduces the principal slightly, with the share going to principal growing as the loan ages.
- Amortization
- The process of paying off a loan through equal scheduled payments, where early payments are mostly interest and later payments are mostly principal.
- PITI
- Short for principal, interest, taxes, and insurance. It describes the full monthly housing payment that lenders usually evaluate, sometimes with HOA dues added.
- Escrow
- An account your loan servicer uses to collect and pay your property taxes and homeowners insurance on your behalf, typically funded as part of each monthly payment.
- Private mortgage insurance (PMI)
- Insurance that protects the lender, not you, and is commonly required on conventional loans when the down payment is less than 20 percent of the home price.
- Loan-to-value ratio
- The loan amount divided by the home's value. A 20 percent down payment equals an 80 percent loan-to-value ratio, which many lenders treat as a key threshold.
Related guides
Frequently Asked Questions
Does this include property taxes and insurance?+
Yes, if you fill in the optional annual tax and insurance fields, they're added to your monthly principal & interest payment for a full PITI estimate.
What interest rate should I use?+
Use current rates for your credit profile and loan type — check with a few lenders, since rates vary based on credit score, loan type, and market conditions.
Does a bigger down payment always help?+
A larger down payment reduces your loan amount and monthly payment, and can help you avoid private mortgage insurance (PMI) if it reaches 20% of the home price.
Does the calculator account for PMI (private mortgage insurance)?+
No — the annual insurance field is meant for homeowners insurance, not PMI. If your down payment is below 20% of the home price, lenders typically require PMI, which usually runs about 0.5%–1.5% of the loan amount per year; add that amount into the annual insurance field yourself if you want it reflected in your total monthly payment.
What happens if my down payment is larger than the home price?+
The loan amount can't go negative — the calculator caps it at $0 in that case, which would show principal & interest as $0/month. That's an edge case built in as a safeguard, and seeing a $0 payment is a sign to double-check your home price and down payment entries rather than an actual all-cash purchase result.
Why is my monthly payment mostly interest in the early years?+
Interest is charged on the remaining balance each month, and at the beginning that balance is as large as it will ever be. A level payment therefore covers a lot of interest and only a small slice of principal at first. As the balance shrinks, the interest portion falls and more of each payment goes to principal. That is why extra payments made early in the loan save more interest than the same extra payment made years later.
How much of my income should go to a mortgage?+
There is no single correct number, but lenders often check what share of gross monthly income goes to housing and to all debts combined, and many aim to keep housing around a quarter to a third of income. Your own limit depends on other debts, savings goals, childcare, and local costs. Use the total monthly payment from this tool, then compare it with your actual budget rather than relying only on a ratio.
Will making one extra payment a year shorten my loan?+
Yes. An extra payment applied to principal reduces the balance, so less interest accrues in every later month, and the loan ends sooner. The exact savings depend on your rate, balance, and when the extra payment is made. This calculator does not model prepayment, so use a dedicated amortization tool to see the schedule, and confirm with your servicer that extra money is applied to principal.
Is it better to put more down or keep cash in savings?+
A larger down payment lowers the loan, the monthly payment, and total interest, and may remove the need for mortgage insurance. But draining your savings leaves you exposed to repair bills, job changes, or moving costs. Many buyers keep an emergency reserve and some cash for immediate home expenses before maximizing the down payment. Model several down payment amounts here and weigh them against the cash cushion you want to keep.
Why does the lender's quote differ from this calculator's result?+
Lender quotes often include mortgage insurance, escrow cushions, fees rolled into the loan, or different tax assumptions. The rate may also reflect points or a specific lock period. The amortization math itself is standard, so if you enter the same loan amount, rate, and term, principal and interest should match closely. Differences usually come from those added items or from rounding, which is why you should compare line by line with the lender's loan estimate.
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<a href="https://everyfix.net/tools/mortgage-calculator/">Mortgage Calculator</a> by <a href="https://everyfix.net">EveryFix</a>Related Tools
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