Mortgage Calculator
Estimate your monthly payment and total loan cost before you commit to a purchase or refinance.
Need a walkthrough? Read the Mortgage Calculator Guide.
Mortgage Calculator
How Mortgage Calculation Works
The Mortgage Calculator estimates your monthly mortgage payment including principal, interest, property taxes, and insurance (PITI). Enter the home price, down payment, interest rate, and loan term to understand the true monthly cost of homeownership.
Formula
Monthly P and I = P x [r(1+r)^n] / [(1+r)^n - 1] where P=loan amount, r=monthly interest rate, n=number of payments
Key Features
- ✓Full PITI payment breakdown (Principal, Interest, Tax, Insurance)
- ✓Adjustable down payment with PMI calculation
- ✓Amortization schedule showing equity buildup
- ✓Compare 15-year vs. 30-year loan scenarios
Pro Tip
A 20% down payment eliminates Private Mortgage Insurance (PMI), which typically costs 0.5-1% of the loan amount annually. If you cannot put 20% down, factor PMI into your monthly budget.
Home budget check
Estimate the full ownership payment, not just principal and interest
Mortgage affordability depends on the full monthly housing cost. Use the result with taxes, insurance, down payment, closing costs, and future maintenance before making an offer.
Methodology
- Calculate principal and interest from loan amount, interest rate, and term.
- Add property taxes, insurance, HOA fees, and mortgage insurance where relevant.
- Compare scenarios with different down payments, rates, and terms before locking a lender decision.
Practical examples
- A $300,000 loan at 6 percent for 30 years has principal and interest near $1,799 per month.
- Adding $450 taxes and $120 insurance puts the estimated payment near $2,369 before HOA or maintenance.
- A lower rate can create meaningful savings, but closing costs decide whether refinancing pays off.
Common mistakes to avoid
- Do not use principal and interest as the full housing budget.
- Do not forget closing costs, moving costs, repairs, and emergency reserves.
- Do not compare fixed and variable rates without modelling payment shock risk.
When to use this calculator
- Before making an offer to confirm the payment fits your budget.
- When comparing rate options or loan terms.
- While planning a refinance to see potential savings.
Worked example
A $300,000 loan at 6.0% for 30 years produces a principal-and-interest payment of about $1,799 per month. Add $450 for property taxes and $120 for insurance to estimate a total monthly cost near $2,369.
How to interpret your results
Focus on the total monthly cost, not just the principal-and-interest figure. If the payment is too high, adjust price, down payment, or term and rerun the numbers before you commit.
What to do next
Validate ownership costs and compare loan structures before locking in a lender.
Guides: Mortgage Calculator Guide, Fixed vs Variable Mortgage.
Related tools: Closing Cost Calculator and Property Tax Estimator.
Compare loan types: Fixed vs Variable Mortgage.
Need more room in the budget before you buy? Test a payoff plan with Debt Payoff Calculator.
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