CalcComet

Mortgage Calculator

Enter your home price, down payment, and interest rate to see your monthly payment instantly.

Monthly Payment
$2,022.62
principal & interest only
Loan Amount
$320,000
Total Interest
$408,142
Total Cost
$728,142
LTV
80.0%
Principal$320,000
Total Interest$408,142
Total Cost$728,142
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20.0%
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yr
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How It Works

Your monthly mortgage payment is made up of two parts: principal (paying down what you borrowed) and interest (the lender's fee for the loan). This calculator uses the standard amortization formula, which spreads equal monthly payments across the full loan term.

In the early years, most of each payment goes toward interest. Over time, that flips — more goes toward principal. By the final payment, you've paid off the entire loan.

LTV (Loan-to-Value) is your loan amount divided by the home price, expressed as a percentage. On a $400,000 home with $80,000 down, your LTV is 80%. Most lenders require an LTV of 80% or below to avoid paying PMI (Private Mortgage Insurance), which is an extra monthly cost not included in this calculator.

What Affects Your Payment

  • Interest rate — even a half-percent difference adds up fast. On a $320,000 loan, going from 6.5% to 7.0% adds about $100/month and over $36,000 in total interest over 30 years.
  • Loan term — a 15-year loan has a higher monthly payment but saves an enormous amount in interest. A $320,000 loan at 6.5% costs about $175,000 in interest over 30 years, but only about $88,000 over 15 years.
  • Down payment — a larger down payment reduces your loan size, lowers your monthly payment, and may qualify you for a better rate.

What This Calculator Doesn't Include

Your actual monthly housing cost will likely be higher than what you see here. This calculator only shows principal and interest. Most homeowners also pay:

  • Property taxes — typically 1–2% of home value per year, paid monthly into escrow
  • Homeowner's insurance — usually $100–$200/month depending on the home
  • PMI — required if your down payment is less than 20% (LTV above 80%)
  • HOA fees — if applicable to your property

A rough rule of thumb: budget an extra $400–$800/month on top of your P&I payment for these costs.

Tips

  • Shop multiple lenders. Rates vary by 0.5–1% between lenders for the same borrower. On a $300,000 loan, that's a difference of $90–$180/month.
  • Put 20% down if you can. It eliminates PMI, reduces your loan, and often gets you a better rate. On a $400,000 home, 20% down is $80,000 — not easy, but the monthly savings are significant.
  • Consider a 15-year loan if the payment fits. You'll pay roughly double in monthly principal, but cut your total interest cost nearly in half.