Finance & business
Mortgage Calculator
Enter your home price, down payment, loan term and interest rate to see your monthly principal & interest, the full monthly payment including property tax and home insurance, and the total cost over the life of the loan. Most American homebuyers finance with a 30-year fixed mortgage, but this tool lets you model any term so you can weigh a lower monthly payment against the interest savings of a shorter loan. Because your real housing bill is more than just principal and interest — lenders bundle property taxes and insurance into an escrow account known as PITI — entering those annual amounts gives you a far more realistic monthly number. It updates as you type, runs entirely in your browser, and shows the exact amortization formula below.
Mortgage details
principal, interest, tax & insurance
Assumes a fixed rate, equal monthly payments and constant tax/insurance. PMI, HOA fees and closing costs are not included.
How the mortgage calculator works
Your loan amount is the home price minus your down payment. The monthly principal & interest is found with the standard amortization formula — the same fixed-rate math lenders use. Each month you pay the same principal & interest amount; early payments are mostly interest and later payments are mostly principal.
If you enter annual property tax or home insurance, they are divided by 12 and added on top to give your full monthly housing payment (often called PITI).
Amortization formula
M = P × r × (1 + r)ⁿ ÷ [ (1 + r)ⁿ − 1 ]where: P = loan amount = home price − down payment r = monthly interest rate = annual rate ÷ 12 ÷ 100 n = number of monthly payments = term in years × 12 M = monthly principal & interest
Total monthly payment is M + tax/12 + insurance/12. Total interest is (M × n) − loan amount. When the rate is 0%, principal & interest reduces to P ÷ n.
Notes & assumptions
- Assumes a fixed interest rate for the entire term and equal monthly payments.
- Property tax and home insurance are treated as constant annual amounts split evenly across 12 months.
- Does not include PMI, HOA dues, closing costs or escrow adjustments.
- Calculations are for general information only — verify with your lender before relying on them.
Worked example
Imagine buying a $300,000 home with a $60,000 down payment (20%) on a 30-year fixed mortgage at 6.5%. You finance a $240,000 loan, and the amortization formula returns monthly principal & interest of about $1,517. Add $3,600 a year in property tax ($300/month) and $1,200 a year in homeowners insurance ($100/month) and your full PITI payment comes to roughly $1,917. Over the 30-year life of the loan you'd pay more than $306,000 in interest alone — which is why even a half-point lower rate, or a switch to a 15-year term, can save tens of thousands of dollars.
Frequently asked questions
What's included in a monthly mortgage payment?
A typical U.S. mortgage payment has four parts, often abbreviated PITI: principal, interest, taxes and insurance. Principal and interest pay down the loan itself, while your lender usually collects property tax and homeowners insurance in an escrow account and pays those bills on your behalf. If you put down less than 20%, private mortgage insurance (PMI) is commonly added too, and homes in certain communities may also owe HOA dues.
What is PMI and when do I have to pay it?
Private mortgage insurance protects the lender if you default, and it's typically required when your down payment is below 20% of the home price on a conventional loan. It's added to your monthly payment until you build enough equity — usually around 20% — at which point you can request to cancel it. This calculator doesn't include PMI, so add it separately if your down payment is under 20%.
How do property tax and insurance escrow work?
Rather than billing you a large lump sum once or twice a year, most lenders divide your annual property tax and homeowners insurance into 12 equal pieces and collect them with each mortgage payment. That money sits in an escrow account, and the lender pays the tax and insurance bills when they come due. Because rates and assessments change, your escrow portion can rise or fall from year to year.
Should I choose a 15-year or 30-year mortgage?
A 30-year loan keeps your monthly payment low and is the most popular choice for U.S. buyers, but you pay far more interest over time. A 15-year loan has a higher monthly payment yet usually a lower rate and dramatically less total interest, helping you build equity faster. The right choice depends on your budget, how long you plan to stay, and whether you value cash-flow flexibility or long-term savings more.
How much house can I afford?
A common rule of thumb is to keep your total housing payment (PITI) at or below 28% of your gross monthly income, and all debt payments under about 36% — the so-called 28/36 rule lenders often use. Your down payment, interest rate, credit score and other debts all factor in. Use this calculator to test different home prices and down payments until the monthly payment fits comfortably within your budget.