How to use the Mortgage Calculator

Quick start

1. Open the Mortgage Calculator.
2. Enter the home price and down payment as dollar amounts, not percentages.
3. Use the first example, "Starter estimate: $400,000 home, $80,000 down, 6.5%, 30 years", if you want to see a filled-out estimate before entering your own values.
4. Calculate, read the formula line, then copy the result only after the amounts, rates, and term look right.

Best uses

Use this guide when one of these tasks matches what you are trying to do.

• Estimate monthly mortgage principal and interest from home price, down payment, rate, and term.
• Add common monthly ownership costs such as property tax, insurance, PMI, and HOA dues.
• Compare how down payment or rate changes affect monthly payment and total interest.
• Check loan-to-value before discussing PMI or lending options.

What this calculator is for

The Mortgage Calculator is for a first-pass monthly housing estimate. It separates principal and interest from property tax, insurance, PMI, and HOA costs so the monthly number is easier to read.

Use it when you want to: Estimate monthly mortgage principal and interest from home price, down payment, rate, and term. Add common monthly ownership costs such as property tax, insurance, PMI, and HOA dues.

What to enter

Finance estimates are sensitive to small input changes. Check whether a field expects a monthly amount, annual amount, dollar value, or percent before calculating.

• Enter the home price and down payment as dollar amounts, not percentages.
• Use the loan rate and term you want to compare, such as 6.5% for 30 years.
• Add property tax per year, then monthly insurance, PMI, and HOA only when those costs apply.

Example walkthrough

Try the calculator example: Starter estimate: $400,000 home, $80,000 down, 6.5%, 30 years. The example result is Monthly P&I plus optional escrow-style costs.

• For a $400,000 home with $80,000 down, the loan amount is $320,000.
• The calculator finds principal and interest first, then adds the monthly ownership costs you entered.

Formula and steps

The calculator uses the fixed-payment loan formula for principal and interest, then adds monthly property tax, insurance, PMI, and HOA amounts you enter.

The formula line on the calculator page is there so the number is not a black box. Read it before using the answer in a budget, comparison, or planning note.

How to read the answer

Start with the headline result, then use the supporting metrics to understand what made the result larger or smaller.

• Read principal and interest separately from the total monthly payment.
• Loan-to-value helps you see how much of the home price is financed.
• Total interest is the interest over the full loan term if the rate and payment stay fixed.

Common mistakes to avoid

Most bad finance estimates come from mixing rates, terms, monthly amounts, and annual amounts. The other common mistake is using a planning estimate as if it were a final quote.

• Do not treat this as a lender Loan Estimate or final approval.
• Do not enter annual insurance in a monthly insurance box.
• Do not forget that closing costs, escrow changes, and local taxes can change the real payment.

What to try next

A related calculator can help check the same money question from another angle before you rely on one result.

• Use Amortization Calculator to test extra payments.
• Use Interest Rate Calculator if you only know the payment quote.

Sources and estimate notes

This guide links to public financial, consumer, statistical, or tax references where they are useful for understanding the calculator context.

Source links improve transparency, but they do not turn a quick calculator into professional advice or a final loan, tax, payroll, or investment answer.

• Consumer Financial Protection Bureau: Mortgage key terms

Examples from the calculator

Common questions

Related tools

• Loan Calculator Estimate a fixed monthly loan payment and total interest.
• Amortization Calculator Estimate payoff time, total interest, and extra-payment savings.
• Interest Rate Calculator Estimate annual interest rate from principal, payment, and term.

History, privacy, and copying

Recent answers stay visible in the page while you work. The history is kept only in the current browser tab and is not sent to a server.

Copy answer copies the expression and result so you can paste it into notes, homework, a message, or another document.