Mortgage Calculator
Estimate your monthly mortgage payment including principal, interest, taxes and insurance.
About the Mortgage Calculator
This mortgage calculator estimates your full PITI monthly payment — Principal, Interest, Taxes, and Insurance — plus private mortgage insurance (PMI) when your down payment is below 20%. Enter the home price, your down payment, the interest rate, the loan term, and your annual property tax and homeowners insurance estimates, and the tool returns a realistic monthly payment comparable to what your lender's Loan Estimate will show.
Many online mortgage calculators show only principal and interest, which dramatically understates the true cost of homeownership. Property taxes typically run 0.5-2.5% of home value per year depending on the state; insurance adds $1,000-$2,500 annually; and PMI can add 0.5-1.5% of the loan balance each year until you reach 78% loan-to-value. Combined, these can add $300-$800/month on a typical $350,000 home.
This tool is designed for fixed-rate conventional mortgages in the U.S. market. For FHA, VA, and adjustable-rate loans, the structure of fees differs and you should consult a licensed mortgage loan originator.
How It Works
The calculator computes the principal-and-interest portion using the standard amortization formula:
M = (P * r) / (1 - (1 + r)^(-n))Where P = loan principal (home price minus down payment), r = monthly interest rate (annual rate / 12), and n = number of monthly payments (years * 12).
Property tax and homeowners insurance are divided by 12 to convert annual figures to monthly. PMI is triggered automatically when your down payment is less than 20% of the home price, using an industry-standard 0.5% annual rate on the loan principal divided by 12. PMI auto-cancels at 78% loan-to-value under federal law (the Homeowners Protection Act of 1998).
The 28/36 rule is the standard affordability guideline: your total housing payment (PITI) should not exceed 28% of gross monthly income, and total debt (housing plus all other loans) should not exceed 36%. Violating 28/36 does not automatically disqualify you, but it significantly raises the risk of becoming house-poor.
Worked Examples
Suppose you buy a $350,000 home with $70,000 down (20%) at 6.8% interest for 30 years, with $4,200 annual property tax and $1,400 annual insurance.
- Loan principal: $350,000 - $70,000 = $280,000
- Monthly rate: 6.8% / 12 = 0.5667% = 0.005667
- Payments: 30 * 12 = 360
- P&I payment: 280,000 * 0.005667 / (1 - 1.005667^(-360)) = $1,824.07/month
- Property tax: $4,200 / 12 = $350/month
- Insurance: $1,400 / 12 = $116.67/month
- PMI: $0 (down payment is exactly 20%)
- Total PITI: $1,824.07 + $350 + $116.67 = $2,290.74/month
If your down payment were only 10% ($35,000), PMI would add about $131/month, pushing the total to $2,422/month. Reaching 20% equity triggers PMI cancellation — a meaningful milestone worth pursuing.
When to Use This Tool
Use this mortgage calculator when:
- Comparing homes at different price points to see what fits your budget
- Deciding between a 15-year and 30-year term (15-year has lower rate, higher payment, far less total interest)
- Figuring out how much down payment you really need to avoid PMI
- Estimating whether refinancing at a lower rate makes sense after closing costs
- Determining if you can afford the home under the 28/36 rule
- Comparing a conventional loan with an FHA loan's mortgage insurance premium (MIP)
- Planning for the year when PMI auto-cancels at 78% LTV
Closing costs typically run 2-5% of the loan amount and are not included in this calculator's monthly payment. Budget separately for them.
Limitations & Disclaimer
This calculator models a fixed-rate conventional mortgage for the U.S. market. It does not handle FHA MIP (which persists for the life of the loan in most cases), VA funding fees, USDA guarantee fees, adjustable-rate mortgages, interest-only periods, or balloon structures. PMI is estimated at an industry-typical 0.5% annual rate; your actual PMI rate may vary based on credit score and loan-to-value. Property tax and insurance figures are user-entered and may diverge from lender escrow analyses. This is an educational estimate, not a Loan Estimate or a binding offer. Consult a licensed mortgage originator for official figures. See our disclaimer for full terms.
Frequently Asked Questions
What is the 28/36 rule?
Your total monthly housing payment (PITI: principal, interest, taxes, insurance, and HOA) should not exceed 28% of your gross monthly income, and your total monthly debt (housing plus car loans, student loans, credit cards) should not exceed 36%. Lenders use this as a quick affordability gate.
When does PMI cancel?
Under the federal Homeowners Protection Act (1998), PMI auto-cancels at 78% loan-to-value based on the original amortization schedule, provided you are current on payments. You can request earlier cancellation at 80% LTV if you have a clean payment history and can prove the home's value.
How much down payment do I need?
Conventional loans require at least 3% down (5% is more common). Putting 20% down eliminates PMI entirely. FHA loans require 3.5% down but carry mortgage insurance premiums (MIP) for the life of the loan in most cases.
Should I get a 15-year or 30-year mortgage?
15-year loans have lower interest rates (~0.5-0.75% lower) and build equity much faster — you'll pay roughly 60% less total interest. But the monthly payment is about 25-30% higher. Choose 15-year only if you can comfortably afford the payment and still have an emergency fund.
Are property taxes included in this calculator?
Yes — the annual property tax field is divided by 12 and added to your monthly payment. Enter your best estimate; tax rates vary widely by jurisdiction (0.3% in Hawaii, 2.5% in parts of New Jersey and Illinois).
Does this include HOA fees or closing costs?
No. HOA fees (if any) should be added to your monthly housing cost separately. Closing costs (2-5% of loan amount) are paid upfront at the closing table and are not part of the monthly payment. They typically include lender fees, title insurance, appraisal, and prepaid escrow.
Last updated: July 21, 2026 · Author: HT99 Tools Editorial Team · Reviewed by: HT99 Tools Editorial Team