Mortgage Calculator

How to Use the Mortgage Calculator

Use our free mortgage calculator to estimate your monthly mortgage payments. Enter the home price, down payment, interest rate, and loan term to see your monthly payment and total cost. The calculator is designed to give a fast answer, but the quality of the answer still depends on accurate inputs and a clear idea of what decision you are trying to support.

1. Enter Home Price, Down Payment, and Annual Interest Rate using the same units you plan to compare or report.
2. Add Loan Term and review the inputs before calculating.
3. Read the main monthly payment first, then use the supporting outputs to understand the trade-offs behind that result.
4. Compare your numbers with the worked examples below if you want a quick reasonableness check.

What Your Result Means

The monthly payment is the principal-and-interest portion only, which makes it useful for comparing financing structures before layering in taxes, insurance, or HOA costs. On this page, the primary output is monthly payment.

Scenario 1: $300,000 home with 20% down at 6.5% for 30 years. Inputs used: homePrice: 300000, downPayment: 60000, rate: 6.5, term: 360. Example result: $1,516.96/month. A $240,000 mortgage at 6.5% over 30 years results in a monthly P&I payment of $1,516.96, with $306,106.77 in total interest. Scenario 2: $400,000 home with 10% down at 7% for 30 years. Inputs used: homePrice: 400000, downPayment: 40000, rate: 7, term: 360. Example result: $2,395.09/month. A $360,000 mortgage at 7% costs $2,395.09/month, totaling $502,232.03 in interest over 30 years.

Formula and Assumptions

Core formula: same amortization model as loans, applied to home price minus down payment. The mortgage calculator converts home price and down payment into a loan amount, then applies the amortization formula to estimate principal-and-interest payments.

1. This page does not include taxes, insurance, or PMI.
2. Longer terms reduce monthly payments but increase total interest.

When to Use This Mortgage Calculator

Use this calculator when comparing home prices, down payments, rates, and loan terms before requesting lender quotes. Related paths for follow-up analysis include loan calculator, compound interest calculator, and roi calculator.

Common Mistakes to Avoid

Most bad outputs come from a few repeated input errors or interpretation mistakes. Use this short checklist before relying on the result.

1. Assuming the result includes taxes, insurance, PMI, or maintenance.
2. Entering a down payment percent as a dollar amount.
3. Optimizing only for monthly payment while ignoring lifetime interest cost.