ToolVaults

Mortgage Calculator

Calculate your monthly mortgage payment, total interest, and a year-by-year amortization schedule. All math runs in your browser.

Runs 100% in your browser — nothing is uploaded.
Monthly payment
$2,528.27
Total interest
$510,177.95
Total paid
$910,177.95

Estimate only — does not include property tax, insurance, PMI, HOA, or origination fees. Verify with a licensed mortgage broker before making decisions.

How to use

  1. 1
    Enter the loan amount

    The purchase price minus your down payment. That is what you actually finance.

  2. 2
    Enter the annual interest rate

    The APR your lender quoted. Enter 6.5 for 6.5%.

  3. 3
    Pick the term

    Usually 15 or 30 years. Shorter term = higher monthly, less total interest.

  4. 4
    Read the results

    Monthly payment, total interest paid over the loan, and the year-by-year amortization schedule.

Examples

$300,000 · 6.5% · 30 years
Input
Principal $300,000 · Rate 6.5% · Term 30 years
Output
Monthly: $1,896.20 · Total interest: $382,633
Classic first-house scenario. Over half of what you pay is interest.
$500,000 · 5.75% · 15 years
Input
Principal $500,000 · Rate 5.75% · Term 15 years
Output
Monthly: $4,152.67 · Total interest: $247,481
Same principal at a shorter term — payment doubles, but total interest is ~35% lower.
$200,000 · 0% · 30 years (interest-free family loan)
Input
Principal $200,000 · Rate 0% · Term 30 years
Output
Monthly: $555.56 · Total interest: $0
Formula simplifies to P / n when rate is zero.

Frequently asked

What does this NOT include?

Property taxes, homeowner's insurance, private mortgage insurance (PMI), HOA fees, and origination or discount points. Real monthly cost is typically 15–30% higher than the base payment shown here.

How is the monthly payment formula derived?

Standard amortizing loan formula: P × [r(1+r)^n] / [(1+r)^n − 1], where P is principal, r is monthly rate (annual / 12), and n is total months. When rate = 0, it simplifies to P / n.

Why does the schedule show only yearly snapshots?

To keep the UI scannable. A 30-year mortgage has 360 rows; showing 30 is enough to see the interest → principal shift over time. The full schedule is computed and can be exported in a future update.

Related tools