Mortgage Calculator
Calculate your monthly mortgage payment, see PMI, taxes, HOA and a full amortization schedule
What Is a Mortgage Calculator?
A mortgage calculator helps you estimate your monthly home loan payment based on the home price, down payment, interest rate, and loan term. You can also add costs like property tax, home insurance, PMI, and HOA fees to see a more realistic monthly total.
How Mortgage Payments Work
Each mortgage payment is split into principal and interest. At the start of the loan, a larger share goes toward interest. Over time, more of each payment goes toward principal as the loan balance decreases.
Mortgage Payment Formula
The standard monthly payment formula is:
M = P × [r(1+r)n] / [(1+r)n − 1]
Where M is the monthly payment, P is the loan amount, r is the monthly interest rate, and n is the total number of monthly payments.
Input Guide
Home Price
The total purchase price of the home before the down payment is subtracted.
Down Payment (%)
The amount you pay upfront in cash. A larger down payment lowers your loan amount and monthly payment.
Interest Rate
The annual rate charged by your lender. Even a small change can affect the total cost of the loan.
Loan Term
The number of years you will take to repay the mortgage. Shorter terms usually mean higher monthly payments but less total interest.
Property Tax, Insurance, PMI & HOA
These optional inputs help you estimate your full monthly housing cost, not just principal and interest.
Extra Payments
You can add extra monthly or one-time payments to see how much faster you can pay off the loan and reduce interest.
Why Use This Calculator?
- Estimate your monthly mortgage payment quickly.
- Compare different loan scenarios before you buy.
- See how taxes, insurance, PMI, and HOA fees affect your budget.
- Check how extra payments can reduce total interest.
Common Mistakes to Avoid
- Ignoring property tax and insurance.
- Assuming PMI will last for the full loan term.
- Comparing loans by monthly payment only.
- Forgetting HOA fees when budgeting.
Mortgage Tips
- Get pre-approved before house hunting.
- Compare more than one lender.
- Try both shorter and longer terms before deciding.
- Use extra payments only if there is no prepayment penalty.
Limitations
- Results are estimates, not final lender quotes.
- Closing costs are not included.
- Property tax and insurance must be entered by the user.
Worked Examples
First-Time Buyer (Low Down Payment)
Home Price: $250,000
Down Payment: 5% ($12,500)
Loan Amount: $237,500
Interest Rate: 6.75%
Loan Term: 30 years
Monthly Payment: $1,540.65
Total Payment: $554,634
Total Interest: $317,134
A small down payment keeps upfront cash low, but PMI is almost certainly required until the balance drops to 80% of the home price, and total interest is higher because more is borrowed.
10% Down Payment
Home Price: $300,000
Down Payment: 10% ($30,000)
Loan Amount: $270,000
Interest Rate: 6.5%
Loan Term: 30 years
Monthly Payment: $1,706.67
Total Payment: $614,401
Total Interest: $344,401
Doubling the down payment percentage from 5% to 10% lowers the loan amount and the monthly payment, and typically shortens how long PMI is required.
20% Down Payment (No PMI)
Home Price: $300,000
Down Payment: 20% ($60,000)
Loan Amount: $240,000
Interest Rate: 6.5%
Loan Term: 30 years
Monthly Payment: $1,517.04
Total Payment: $546,134
Total Interest: $306,134
Reaching 20% down avoids PMI entirely, which lowers the effective monthly housing cost even though the mortgage math itself is similar to the 10%-down example.
15-Year Mortgage
Home Price: $300,000
Down Payment: 20% ($60,000)
Loan Amount: $240,000
Interest Rate: 6%
Loan Term: 15 years
Monthly Payment: $2,025.36
Total Payment: $364,565
Total Interest: $124,565
The monthly payment is considerably higher than the 30-year version below, but total interest is less than half — a common trade-off between cash flow and long-term cost.
30-Year Mortgage (Same Loan)
Home Price: $300,000
Down Payment: 20% ($60,000)
Loan Amount: $240,000
Interest Rate: 6%
Loan Term: 30 years
Monthly Payment: $1,439.04
Total Payment: $518,054
Total Interest: $278,054
Compared with the 15-year example above, stretching the same loan to 30 years cuts the monthly payment by about 29% but more than doubles the total interest paid.
Low Interest Rate Scenario
Home Price: $300,000
Down Payment: 20% ($60,000)
Loan Amount: $240,000
Interest Rate: 4%
Loan Term: 30 years
Monthly Payment: $1,145.76
Total Payment: $412,474
Total Interest: $172,474
A lower rate on an identical loan amount and term reduces total interest by well over $100,000 compared to the 6% example — rate shopping matters.
High Interest Rate Scenario
Home Price: $300,000
Down Payment: 20% ($60,000)
Loan Amount: $240,000
Interest Rate: 8%
Loan Term: 30 years
Monthly Payment: $1,761.12
Total Payment: $634,003
Total Interest: $394,003
The same loan at a higher rate costs over $220,000 more in interest than the low-rate scenario, even though the loan amount never changed.
Frequently Asked Questions
How accurate is this mortgage calculator?
It gives a close estimate using the standard mortgage formula. Your final payment may vary slightly because lenders round differently or add fees.
What is included in the monthly payment?
The calculator can include principal, interest, property tax, home insurance, PMI, and HOA fees for a more realistic monthly total.
How is the down payment calculated?
The calculator multiplies your down payment percentage by the home price to find the amount you pay upfront.
What is PMI?
PMI is private mortgage insurance. It is usually required when your down payment is below 20% and may stop once your loan balance drops enough.
What is the difference between fixed and adjustable-rate mortgages?
A fixed-rate mortgage keeps the same rate and payment for the full term. An adjustable-rate mortgage can change later based on market conditions.
Do I need to include property tax and insurance?
They are optional in the calculator, but most lenders require them, so adding them gives a more accurate monthly cost.
What are HOA fees?
HOA fees are monthly charges for shared community costs such as maintenance, landscaping, or amenities.
Does this calculator include closing costs?
No. Closing costs are separate one-time fees paid at the time of purchase.
Can extra payments save money?
Yes. Extra payments reduce the loan balance faster and can lower total interest and shorten the loan term.
Should I choose a 15-year or 30-year mortgage?
A 15-year mortgage costs less in total interest, while a 30-year mortgage gives a lower monthly payment.
How much house can I afford?
A common rule is to keep your total housing payment around 28% of your gross monthly income.
Does my credit score affect the rate?
Yes. A better credit score usually helps you qualify for a lower interest rate.
Why does a small rate change matter?
Even a small rate change can make a big difference because interest is charged over many years.
Can I pay off my mortgage early?
Many loans allow early payoff, but some may charge a penalty, so check your loan terms first.
Conclusion
A mortgage is likely the largest loan most people ever take on, so understanding exactly how price, down payment, rate, term, and extra costs interact is worth the few minutes it takes. Use this calculator to compare scenarios, test the impact of extra payments, and build a realistic monthly budget before you sign anything.