What this calculator does
Find out what your house payment will really be each month. This calculator adds up the loan payment, property tax, home insurance, mortgage insurance (PMI) and HOA dues. It also shows how much interest you'll pay in total, how your balance shrinks year by year, and when the loan is paid off. If you pay PMI, it shows roughly when that stops, too.
Lenders often quote only the loan part of the payment, called principal and interest. But most people also pay property tax and insurance through their lender each month, in an account called escrow. If you put down less than 20%, the lender may add PMI. And if you have an HOA, it bills its own dues. Putting all of these together gives a number close to what actually leaves your bank account each month.
Where it's used
Why this math matters outside the classroom:
- Choosing a loan term. Buyers compare a $350,000 loan at 6% over 30 years, about $2,098 a month, with 15 years at about $2,953 a month.
- Comparing rates. Dropping the rate from 7% to 6% on a $300,000, 30-year loan cuts the monthly payment by about $197.
- Sizing a down payment. Putting 20% rather than 10% down on a $400,000 home lowers the amount borrowed from $360,000 to $320,000.
- Lifetime interest. Multiplying the monthly payment by the number of payments shows how much of a loan's total cost is interest.
- Refinancing decisions. Homeowners weigh a refinance by comparing today's payment with the payment on the remaining balance at the new rate and term.
Grade level and standards: Grades 11–12; Common Core State Standards for Mathematics HSA.SSE.B.4. © Copyright 2010. National Governors Association Center for Best Practices and Council of Chief State School Officers. All rights reserved.
How to use it
- Enter the home price and your down payment, either as a percentage of the price or as a dollar amount.
- Enter the interest rate, the loan term in years and the date the loan starts.
- Enter your yearly property tax and home insurance, either in dollars or as a percent of the price. Add any PMI rate and monthly HOA dues. Leave a cost at 0 if it doesn't apply to you.
- Read your total monthly payment and what it's made of. Then use the table and chart to see how your balance falls and how much interest you've paid by each year.
What the inputs mean
- Down payment
- Switch between a percent of the price and a dollar amount. If your down payment equals the full price, there's nothing to borrow, so the calculator asks you to lower it.
- Interest rate
- Your loan's yearly interest rate. The calculator divides it by 12 to get a monthly rate, because interest is charged every month.
- Loan start date
- The date your loan begins, usually your closing date. The first payment is due a month later. So a 30-year loan that starts in October 2026 has its last payment in October 2056.
- Property tax (per year)
- Property tax varies a lot from place to place. Enter last year's tax bill in dollars, or your area's typical rate as a percent of the price.
- Home insurance (per year)
- What you pay for homeowners insurance in a year. You can guess it as a percent of the price, but a real quote is better.
- PMI rate
- Private mortgage insurance protects the lender if you stop paying. It's usually required on a conventional (non-government) loan when you put down less than 20%. It's a yearly percent of the amount you borrow, and your lender sets the rate. Enter 0 if you don't pay it.
- HOA dues
- Monthly homeowners association or condo dues, if you have them. They're added to the total as you enter them.
Formula and method
loan L = price − down payment i = rate ÷ 100 ÷ 12; n = years × 12 P&I = L × i ÷ (1 − (1 + i)^(−n)); at 0%: P&I = L ÷ n monthly tax = annual tax ÷ 12; monthly insurance = annual insurance ÷ 12 monthly PMI = L × PMI rate ÷ 100 ÷ 12 total = P&I + tax + insurance + PMI + HOA total interest = P&I × n − L balance after k payments = L × (1 + i)^k − P&I × ((1 + i)^k − 1) ÷ i
In the formulas, L is the amount you borrow, i is the monthly interest rate and n is the number of monthly payments. The loan part of your payment comes from a standard formula. It finds the one monthly amount that pays off the loan, with interest, in exactly n months. Everything else is a yearly cost divided by 12.
If you enter tax or insurance as a percent, it's a percent of the home price, not the loan. PMI is a percent of the amount you borrow. The monthly total always includes PMI. Separately, the calculator finds the month your balance is scheduled to fall to 78% of the price, or the halfway point of the loan if that comes first. That's when PMI on a typical US conventional loan ends on its own. It also adds up the PMI you'd pay until then.
For the schedule, each month the calculator charges interest on what you still owe. Whatever is left of the payment after interest pays down the loan. The table groups each year's 12 payments together, and the payoff date is the month of the last payment.
Worked example
A $400,000 home with 20% down, a 6.5% rate over 30 years starting on October 18, 2026, property tax of 1.1% of the price per year, $1,800 a year of insurance, and no PMI or HOA.
- Loan amount: $400,000 − 20% of $400,000 = $320,000.
- Monthly rate: 6.5% ÷ 12 ≈ 0.00541667; number of payments: 30 × 12 = 360.
- Principal and interest: $320,000 × 0.00541667 ÷ (1 − 1.00541667^(−360)) ≈ $2,022.62.
- Property tax: 1.1% × $400,000 = $4,400 a year, or $366.67 a month. Insurance: $1,800 ÷ 12 = $150.00.
- Total: $2,022.62 + $366.67 + $150.00 = $2,539.28.
- Total interest: $2,022.62 × 360 − $320,000 ≈ $408,142.36. In the first year, $20,694.69 goes to interest and only $3,576.72 pays down the loan, leaving $316,423.28.
Result: The estimated monthly payment is $2,539.28, and about 80% of it is principal and interest. Over 30 years you'd pay about $408,142.36 in interest. The last payment falls in October 2056.
Understanding the result
Use the total for budgeting. It's close to what you'd pay each month with an escrow account. On a fixed-rate loan, principal and interest never change, but tax, insurance and HOA dues can go up from year to year.
If property tax and insurance make up a large share of the payment, a cheaper home in a lower-tax area can matter as much as a better interest rate.
The schedule shows why early payments build so little equity, the share of the home you own outright. On a 30-year loan at 6.5%, more of each payment goes to interest than to the loan itself for roughly the first 19 years. Paying a little extra early on, or choosing a shorter loan, cuts your total interest sharply.
Assumptions and limitations
- The interest rate stays the same for the whole loan, and interest is charged each month at the yearly rate ÷ 12.
- You pay once a month, at the end of each month. Payments aren't rounded to the cent.
- Tax and insurance are spread evenly over 12 months. PMI stays a fixed percent of the amount you first borrowed.
- Closing costs, points and any fees added to the loan aren't included.
- It doesn't handle adjustable-rate, interest-only or balloon loans. Use the adjustable-rate mortgage calculator for a loan whose rate changes.
- The monthly total includes PMI every month; when PMI ends is shown separately. You can usually ask your lender to cancel it earlier, once you owe 80% of the original value. FHA and other government loans follow different rules.
- It doesn't model tax or insurance going up over time, or a shortfall in your escrow account.
- This is an estimate. The loan estimate from your lender is the official figure.
Frequently asked questions
What is PITI?
It stands for principal, interest, taxes and insurance, the four parts most lenders consider when they look at a housing payment. This calculator shows PITI plus PMI and HOA dues where they apply.
Do I need to pay PMI, and when does it stop?
On many conventional loans, the lender requires mortgage insurance if you put down less than 20%. It normally ends on its own once your balance is scheduled to reach 78% of the home's original value, and you can ask to drop it at 80%. With 10% down on the default example, that happens after 109 payments. Government-backed loans have their own rules, so check with your lender.
How much of my payment goes to interest at first?
In the first month, the interest is what you owe times the monthly rate. On a $320,000 loan at 6.5%, that's $320,000 × 0.065 ÷ 12 = $1,733.33. So only about $289 of the $2,022.62 payment pays down the loan. Each month after that, a little more goes to the loan and a little less to interest.
How is the payoff date worked out?
The first payment is due one month after the start date, and you pay once a month. So the last payment on a 30-year loan falls 360 months after the start. Paying extra toward the loan moves that date earlier.
Is a 15-year or 30-year mortgage better?
A 15-year loan has a higher monthly payment but costs far less interest overall. That's partly because you pay the balance down faster, and partly because 15-year rates are usually lower. Change the term and rate to compare the two. The right choice depends on how big a payment you can comfortably afford.
Why is my lender's figure a little different?
Lenders round the payment to the cent and may estimate tax and insurance from local records. Some also add a small cushion to your escrow account. Small differences are normal. Big ones usually come from the tax or insurance estimate.
Does a bigger down payment always lower the payment?
Yes. You borrow less, so the loan payment drops, and PMI often shrinks or goes away too. Property tax and insurance are based on the home's value, so they stay the same.
How this calculator is checked
Method: Standard level-payment (annuity) formula with monthly rate = yearly rate ÷ 12; escrow items added as monthly shares of yearly amounts. The calculation is covered by automated tests with known reference values and edge cases. Last updated 2026-10-18. Found a problem? Tell us.
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