Mortgage Calculator
Calculate your monthly mortgage payment, total interest and full amortization schedule for any home loan.
Mortgage Calculator — input your values
What does this financial calculator do?
This mortgage calculator estimates your monthly mortgage payment based on the home price, down payment, interest rate and loan term you enter. It splits the payment into principal and interest, and adds property tax and home insurance so you see the true monthly cost of owning the home.
You also get a full amortization schedule showing exactly how much of every payment goes toward interest versus paying down the loan balance, plus a visual breakdown and a payoff chart. Try adding an extra monthly payment to see how much interest you can save.
Formula and variables
This formula computes the fixed payment that fully repays the loan by the end of the term.
| Symbol | Meaning |
|---|---|
| M | Monthly principal and interest payment |
| P | Loan amount (home price − down payment) |
| r | Monthly interest rate (annual rate ÷ 12) |
| n | Total number of monthly payments (term in years × 12) |
Worked example
You buy a $400,000 home with a $80,000 down payment at 6.5% for 30 years, with $4,800/yr property tax and $1,440/yr insurance.
- Loan amount: $400,000 − $80,000 = $320,000.
- Monthly rate: 6.5% ÷ 12 = 0.5417%.
- n = 30 × 12 = 360 payments.
- Monthly payment M ≈ $2,022.62 (principal and interest).
- Add $400.00 tax and $120.00 insurance per month.
Answer: Total monthly payment ≈ $2,542.62.
Tips and common mistakes
Tips
- A 15-year term usually has a lower rate and halves total interest, but the monthly payment is much higher — compare both before choosing.
- An extra $100 per month on a 30-year mortgage can cut years off the term and save tens of thousands in interest.
- Property tax and insurance are estimates — check your local rates and actual quotes before budgeting.
- Your credit score strongly affects the rate you're offered; a higher score can save thousands over the life of the loan.
Common mistakes to avoid
- Forgetting to include property tax, insurance and maintenance when budgeting for a home.
- Using the home price as the loan amount instead of subtracting the down payment.
- Comparing payments at different terms without accounting for total interest paid.
Mortgage Calculator — frequently asked questions
How is the monthly mortgage payment calculated?
The payment uses the formula M = P × r(1 + r)⿠/ [(1 + r)⿠− 1], where P is the loan amount, r is the monthly interest rate and n is the number of payments. Property tax and insurance are then added on top.
What is an amortization schedule?
It's a table showing each monthly payment split into the interest portion and the principal portion, plus the remaining balance. Early payments are mostly interest; later payments are mostly principal.
How much can I afford for a mortgage?
A common rule of thumb is that your total housing costs (payment, taxes, insurance) should not exceed 28% of your gross monthly income — the '28/36 rule' often used by lenders.
Does a bigger down payment really help?
Yes. A larger down payment reduces the loan amount, may avoid private mortgage insurance (PMI) if you put down 20% or more, and lowers your total interest.
How does extra monthly payment affect my mortgage?
Extra payments go directly toward principal, which shortens the loan term and reduces total interest. Even small extra amounts compound into large savings over 30 years.
Is the result the final payment I'll make?
No — your actual payment can differ due to HOA fees, PMI, escrow adjustments, and rate differences. Use this as an estimate and confirm with a lender.
What is PMI and when can I avoid it?
Private mortgage insurance protects the lender when your down payment is under 20%. You can avoid it with a 20% down payment or ask the lender about alternatives such as piggyback loans.