About this Mortgage Calculator
Understanding your true monthly housing cost is essential for buying a home. Most mortgage calculators only show you the Principal and Interest (PI), which can be misleading. This tool calculates the full PITI (Principal, Interest, Taxes, and Insurance) plus HOA fees and PMI, giving you a realistic picture of your monthly budget.
Who this calculator is for
- Home buyers comparing realistic monthly payment scenarios before touring homes.
- Borrowers who want to include taxes, insurance, HOA dues, and PMI in one payment estimate.
- Anyone building a home-buying budget alongside affordability, down payment, and DTI tools.
When to use it
- Use this calculator when you want a payment estimate that is closer to a lender-style PITI number.
- Run multiple scenarios before making an offer so you can compare rate, term, and down payment tradeoffs.
- Pair this with the affordability and DTI calculators when you want to see whether a target payment fits your budget.
How to use this calculator
- Enter the Home Price and Down Payment amount.
- Set the Interest Rate and Loan Term (usually 30 or 15 years).
- Check Include Taxes & Costs to add Property Tax, Insurance, and HOA fees.
- Review the detailed Breakdown and Amortization Schedule below.
Key assumptions
- This model assumes a fixed-rate mortgage with equal scheduled payments over the full term.
- Property tax, insurance, PMI, HOA, and other costs are treated as flat recurring amounts.
- PMI is estimated from the starting loan balance and does not automatically drop off when equity rises.
Accuracy and testing
Review formula sources, default test cases, assumptions, unit handling, rounding rules, and changelog for this calculator.
How this calculator works
Inputs explained
Home Price
The final negotiated selling price of the home.
Down Payment
The cash you pay upfront. A higher down payment reduces your loan amount and may eliminate the need for PMI.
Interest Rate
The annual interest rate for the loan. This is determined by your credit score and current market conditions.
Property Tax
Annual tax levied by your local government, usually based on the home's assessed value. National average is ~1.1%.
PMI (Private Mortgage Insurance)
Insurance protecting the lender if you default. Usually required if your down payment is less than 20%.
Understanding your results
Example scenarios
Standard 30-Year Fixed
A $400k home with 20% down ($80k) at 6.5% interest results in a loan of $320k. The Principal & Interest is ~$2,022/mo. Adding taxes ($3,200/yr) and insurance ($1,500/yr) brings the total PITI to ~$2,414/mo.
Low Down Payment (FHA/Conventional)
Buying the same $400k home with only 3.5% down ($14k) increases the loan to $386k. This raises P&I to ~$2,440. Plus, you must now pay PMI (~0.5%), adding ~$160/mo. Total monthly cost jumps to ~$3,000.
Key Features
- Detailed PITI Breakdown
- Annual Amortization Schedule
- Includes HOA and PMI options
- Calculates Payoff Date
Things to Keep in Mind
This tool assumes a fixed-rate mortgage. Adjustable Rate Mortgages (ARMs) will have payments that change over time.
Tips & Best Practices
- Experiment with the 'Extra Payment' concept implicitly by shortening the term. Switching from a 30-year to a 15-year term increases monthly payments but saves huge amounts in interest.
- Don't forget closing costs! They usually run 2-5% of the loan amount and are not included in the monthly payment calculation.
- If you put less than 20% down, monitor your equity. Once you hit 20% equity, you can request to cancel PMI.
Glossary of Terms
- PITI
- Principal, Interest, Taxes, and Insurance. The sum of these four components makes up your total monthly mortgage payment.
- Amortization
- The process of spreading out a loan into a series of fixed payments. The loan is paid off at the end of the payment schedule.
- Escrow
- An account held by the lender to pay property taxes and insurance on your behalf.