Quick Answer: What Is a Mortgage Calculator?
A mortgage calculator is a free tool that estimates your monthly home loan payment using four core inputs — home price, down payment, loan term, and interest rate. A complete calculator also adds property taxes, homeowners insurance, HOA fees, and PMI to show your full PITI payment (Principal, Interest, Taxes, Insurance) — the real, all-in cost of owning a home, not just the loan amount.
How to Use This Mortgage Calculator
- 1
Enter your home price. Use the listing price if you're buying, or your home's current market value if you're refinancing.
- 2
Enter your down payment. Type a dollar amount or switch to percentage. 20% avoids PMI; most first-time buyers put down 3–10%.
- 3
Choose your loan term. 30 years lowers your monthly payment; 15 years saves significantly on total interest.
- 4
Enter your interest rate. Use your pre-approval rate if you have one, or a current average rate as a placeholder.
- 5
Click "Show Advanced" to add property tax, homeowners insurance, HOA dues, and PMI for a true PITI estimate.
How Is a Mortgage Payment Calculated?
Lenders calculate your principal & interest payment using a standard amortization formula:
- M = Monthly principal & interest payment
- P = Loan principal (home price minus down payment)
- r = Monthly interest rate (annual rate ÷ 12)
- n = Total number of payments (loan term in years × 12)
Worked example: On a $350,000 home with a 20% down payment ($70,000), your loan principal is $280,000. At a 6.75% annual rate (0.005625 monthly) over 30 years (360 payments):
M ≈ $1,816/month (principal & interest only)
Add property taxes (~$350/mo) and homeowners insurance (~$100/mo), and your full PITI payment lands around $2,266/month.
What's Included in Your Payment (PITI)?
Principal
The portion of your payment that reduces your actual loan balance. Early in your loan, principal makes up a small share.
Interest
The cost of borrowing the money, calculated on your remaining balance. It's highest in the early years of a 30-year loan.
Property Taxes
Set by your local county, billed annually but collected monthly through an escrow account.
Homeowners Insurance
Protects your home against damage. Lenders require it, and the premium is usually divided into your monthly payment.
PMI & HOA Fees
PMI is required when your down payment is below 20%. It protects the lender and is temporary. Use our PMI calculator to learn more. HOA Fees apply to condos/communities; lenders factor them into your affordability.
15-Year vs. 30-Year Mortgage
| Feature | 30-Year Fixed | 15-Year Fixed |
|---|---|---|
| Monthly Payment | Lower | Higher |
| Total Interest Paid | More | Significantly less |
| Equity Build-Up | Slower | Faster |
A 30-year term keeps your monthly payment manageable. A 15-year term costs more per month but saves tens of thousands in interest. Compare options.
Fixed-Rate vs. ARM
A fixed-rate mortgage keeps the same interest rate and payment for the entire loan term. An ARM starts with a lower introductory rate for a set period, then adjusts based on market conditions — adding uncertainty later.
How Much Down Payment Do You Need?
20% is ideal because it eliminates PMI, but it isn't required. Conventional loans often allow 3% down, FHA allows 3.5%, and VA allows 0%. Check out our Down Payment Calculator to run the numbers.
Why Your Interest Rate Matters
A small change in your rate has an outsized effect. On a $280,000 loan, the difference between 6.25% and 6.75% is roughly $80–$90 per month. Over 30 years, that's more than $30,000 in extra interest.
Ready to take the next step?
Compare real-time loan options tailored to your credit score and location to find the lowest possible rate.
Frequently Asked Questions
How accurate is this mortgage calculator?
This calculator uses the same standard amortization formula lenders use to generate Loan Estimates. Your actual payment may vary slightly based on your lender's exact rate, local tax assessments, and the insurance quote you receive — treat this as a highly reliable estimate, not a final number.
Does this calculator include taxes and insurance?
Yes. Click "Show Advanced" to add your property tax rate and homeowners insurance premium. Including both gives you your full PITI payment — the realistic, all-in monthly cost — instead of just principal and interest.
What's the difference between a mortgage calculator and a mortgage payment calculator?
None — they're the same tool. Both estimate your total monthly housing payment, including interest, taxes, and insurance, based on the loan details you enter.
Can I see a full amortization schedule?
Yes. Click "Amortization Schedule" to see a month-by-month (or year-by-year) breakdown of how much of each payment goes to principal versus interest, and how your remaining balance declines over time.
What is considered a good down payment?
20% is the benchmark because it avoids PMI entirely, but most buyers don't wait that long to save it. Many conventional loans accept 3–5% down, and government-backed loans (FHA, VA, USDA) can require even less.
Does my credit score affect my mortgage payment?
Yes, significantly. Higher credit scores typically qualify for lower interest rates, which directly lowers your monthly payment and total interest paid. A 50-80 point credit score difference can shift your rate by half a percentage point or more.
Should I choose a 15-year or 30-year mortgage?
It depends on your priorities. Choose 15 years if minimizing total interest and building equity fast matters most. Choose 30 years if a lower, more flexible monthly payment matters more right now.
What happens if I make extra payments toward my principal?
Extra payments reduce your loan balance directly, which shortens your loan term and cuts the total interest you pay. Even one extra payment a year can knock multiple years off a 30-year mortgage.