Mortgage Calculator

A mortgage calculator estimates your monthly home loan payment — principal, interest, and optionally property taxes, insurance, PMI and HOA dues — based on the home price, down payment, interest rate and loan term you enter. Every figure updates instantly, and the full amortization schedule is computed entirely in your browser.

🕒 Updated September 22, 2026 🏠 Full PITI breakdown 📊 Annual & monthly amortization 🆓 Free forever ⭐ Rate this tool 📖 Read the guide

1 Loan details

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2 Results

Estimated monthly payment
$—
Principal & interest only

Amortization schedule

Calculated entirely in your browser — nothing you enter here is ever sent to a server.

How the monthly payment is calculated

A fixed-rate mortgage payment stays the same every month for the life of the loan, but the split between principal and interest inside that payment changes constantly. Lenders use one standard formula — M = P × [r(1+r)^n] / [(1+r)^n − 1] — where P is the loan amount (home price minus down payment), r is the annual interest rate divided by 12, and n is the total number of monthly payments (loan term in years × 12). Every month, interest is charged on whatever balance is left, so the interest portion is largest at the start and shrinks steadily while the principal portion grows to match — this calculator's amortization schedule below makes that shift visible year by year, or month by month.

Worked example

A $400,000 home with 20% down ($80,000), a 6.5% APR interest rate and a 30-year term produces the following, exactly as this calculator computes it:

Home price:                 $400,000
Down payment:                 $80,000 (20%)
Loan amount:                 $320,000
Interest rate:                   6.5% APR
Loan term:                        30 years

Monthly payment (P&I):        $2,022.62
Total interest paid:         $408,142.36
Total cost (loan + down):    $808,142.36
Payoff date:              January 2057 (first payment: January 2027)

Amortization — selected years
Year 1:  principal $3,576.72   interest $20,694.69   balance $316,423.28
Year 15: principal $8,863.94   interest $15,407.48   balance $232,189.25
Year 30: principal $23,438.03  interest $833.39       balance $0.00

Notice how the principal paid in year 30 ($23,438.03) is more than six times what it was in year 1 ($3,576.72), even though the monthly payment itself never changed — that's the amortization curve in action. For the taxes and insurance side of the full PITI picture, Frost Rank's full tools directory covers more calculators as they launch.

How to calculate your mortgage payment

  1. 1
    Enter the loan basics

    Fill in home price, down payment, loan term and interest rate.

  2. 2
    Add taxes & fees (optional)

    Check "Include property tax, insurance, PMI & HOA" to fold those estimated costs into a full monthly payment figure.

  3. 3
    Read your results

    See the monthly payment breakdown, loan amount, total interest, total cost and payoff date update instantly as you type.

  4. 4
    Review the amortization schedule

    Switch between the annual and monthly views to see exactly how each payment splits between principal and interest over the life of the loan.

Frequently asked questions

By default it's principal and interest (P&I) only, calculated from your loan amount, interest rate and term. Check "Include property tax, insurance, PMI & HOA" to add those estimated costs, giving a full PITI figure closer to what actually leaves your bank account each month.
Standard fixed-rate amortization: M = P × [r(1+r)^n] / [(1+r)^n − 1], where P is the loan amount (home price minus down payment), r is your annual interest rate divided by 12, and n is the number of monthly payments (loan term in years × 12). This is the same formula every mortgage lender uses to price a fixed-rate loan.
Interest is charged on the remaining balance each month, and that balance is largest at the very start of the loan — so the interest portion of a fixed payment is largest early on and shrinks every month as the balance goes down, while the principal portion grows to match. That's why a 30-year loan's amortization schedule looks "front-loaded" toward interest for roughly its first half, even though the payment amount itself never changes.
Private Mortgage Insurance (PMI) is typically required by conventional lenders when your down payment is below 20% of the home price, protecting the lender if you default. It doesn't reduce your loan balance — it's a separate monthly cost, usually 0.5%-1.5% of the loan amount per year, that's typically dropped once you reach 20% equity. Enter your lender's quoted premium in the PMI field to fold it into your total estimate.
No — it assumes one fixed interest rate for the entire loan term, which is what the amortization formula above requires. For an ARM, run the calculator once per rate period using the rate that applies during that period to approximate each phase separately.
No. Every calculation runs entirely in your browser with JavaScript — none of the numbers you enter are ever transmitted to, or stored on, a Frost Rank server.
Rahib Ali
Written & maintained by Rahib Ali
Senior PHP/Laravel Developer & Technical SEO Specialist, 12+ years experience · Updated September 22, 2026

Every figure — monthly payment, total interest, total cost and the full amortization schedule — is computed directly from the standard fixed-rate amortization formula lenders use, not a rounded estimate or lookup table, and recalculates live as you change any input.