Mortgage Calculator
Enter your home price, down payment, interest rate and loan term to see your principal and interest payment, plus estimated property taxes, homeowners insurance and PMI. The calculator uses the standard PMT amortization formula from the CFPB; edit the tax and insurance estimates to match your property.
On a $400,000 home with 20% down at 6.5% for 30 years, the estimated monthly payment is $2,022.62 (principal and interest only) or $2,539.62 including estimated taxes, insurance and PMI.
How to read the badges beside each field: Official figures come from a cited authority; Regional average and Illustrative assumption values are editable placeholders, so replace them with your own quote or county assessment before you rely on the total.
How the mortgage payment is calculated
The monthly principal and interest payment uses the standard PMT (payment) formula from financial mathematics, the same formula used by lenders and described by the CFPB in Understand Loan Options. Property tax, homeowners insurance and PMI are added on top to give the total monthly payment.
r = annual rate / 100 / 12
n = term years x 12
monthly P+I = loan x r x (1 + r)^n / ((1 + r)^n - 1)
total monthly = P+I + property tax + insurance + PMI
Worked example
$400,000 home, 20% down ($80,000), 6.5% rate, 30-year term:
- Loan amount = $400,000 - $80,000 = $320,000
- r = 6.5 / 100 / 12 = 0.00541667 (rounded for display; full precision used in the result)
- n = 30 x 12 = 360
- Monthly P+I = 320,000 x r x (1 + r)^360 / ((1 + r)^360 - 1) = $2,022.62
- Total monthly (with $367 tax + $150 insurance) = $2,539.62
Understanding each payment component
Principal and interest is the core loan repayment. Early payments are mostly interest; as the balance falls, more of each payment goes to principal. This is amortization.
Property tax is collected by local governments and varies significantly by county and state. The default estimate of 1.1% per year is a national average; your actual tax is set by your local assessor. Contact your county assessor or check your most recent tax bill for an exact figure.
Homeowners insurance protects the structure and contents of your home. Lenders require it. The $150/month default is an illustrative figure; your premium will depend on coverage level, location, and insurer.
PMI (private mortgage insurance) is required by most lenders when your down payment is below 20% of the purchase price. It protects the lender, not you. Under the Homeowners Protection Act (12 U.S.C. 4901), you have the right to request cancellation when the loan-to-value ratio reaches 80%. The default estimate of 0.5% of the loan per year is approximate; actual PMI rates vary by lender and borrower profile.
The real cost is the interest, not the payment
The number most buyers fixate on, the monthly principal and interest, is the smallest story this calculator tells. On a $400,000 home with 20% down at 6.5% over 30 years, the principal and interest payment is $2,022.62, but the total interest over the life of the loan is $408,142.36: more than the $320,000 you actually borrowed. Stretching the term lowers the monthly figure and raises that lifetime cost, which is why the 15-year versus 30-year choice matters more than a fraction of a point on the rate.
Property tax, homeowners insurance, and PMI are where the estimate turns personal. The defaults here (1.1% of price a year for tax, about $150 a month for insurance, 0.5% of the loan for PMI) are national placeholders, and each varies enormously: property tax alone can more than double between neighboring counties. Replace them with your own quote and your county assessment before you rely on the total monthly payment.
PMI deserves particular attention, because it is the one line you can eventually delete. It is generally required when your down payment is under 20%, but under the Homeowners Protection Act you can request cancellation once your loan-to-value ratio reaches 80%, and the servicer must drop it automatically at 78% based on the original amortization schedule. Many borrowers keep paying it for years past that point simply because no one told them to ask.
Mortgage calculator: frequently asked questions
What is a good mortgage rate in 2026?
Mortgage rates depend on loan type, term, credit score and market conditions. The CFPB publishes weekly rate surveys at consumerfinance.gov. A 30-year fixed rate considered 'good' varies by borrower; compare at least three lenders for your specific situation.
How much house can I afford?
A common starting guide is keeping your total monthly housing payment (principal, interest, taxes, insurance and PMI) at or below 28% of your gross monthly income. Your lender will calculate a debt-to-income ratio that includes all debts. The CFPB's 'How much house can I afford?' tool at consumerfinance.gov gives a fuller picture.
What is PMI and when can I remove it?
Private mortgage insurance protects the lender if you default. It is typically required when your down payment is less than 20% of the purchase price. Under the Homeowners Protection Act (12 U.S.C. 4901), you can request PMI cancellation when your loan-to-value ratio reaches 80%, and it must be automatically terminated at 78% LTV based on the original amortization schedule.
What is the difference between a 15-year and 30-year mortgage?
A 15-year mortgage has higher monthly payments but a lower interest rate and substantially less total interest paid. A 30-year mortgage has lower monthly payments but higher total cost over the life of the loan. Use the amortization calculator to compare the total interest for each term at your rate.
Official sources
- PMT formula and mortgage concepts: CFPB, Understand Loan Options.
- PMI cancellation rights: CFPB, When can I remove PMI?
- Homeowners Protection Act: 12 U.S.C. Chapter 49, U.S. Government Publishing Office.
Reviewed by the CalculatorHub team, edited by James Graham, 12 June 2026. See our methodology. General information, not financial advice.