Mortgage Calculator

Built by @1calculator · v1 · Mar 2026 · 128,430 runs · 97% found this helpful

Estimate your monthly mortgage payment, total interest and lifetime cost. Adjust the loan, term and rate — every figure updates as you type.

Try a scenario First-time buyer 15-year payoff Jumbo loan $300k · 6% · 30 $500k · 5.5% · 30 $250k · 7% · 15

How It Works

payment = if(rate == 0, loan / (years * 12), loan * (rate / 1200) / (1 - pow(1 + rate / 1200, -years * 12)))

loan = 250,000 · years = 25 · rate = 4.1

Frequently Asked Questions

Does this include property tax and insurance?

No — it calculates principal and interest only. Your lender's full monthly payment adds property tax, homeowner's insurance and possibly mortgage insurance on top.

Is the rate fixed or variable?

The maths assumes one fixed rate for the whole term. If your mortgage is variable, re-run the numbers whenever the rate changes.

How is the monthly payment worked out?

With the standard amortization formula — the same one shown under How it works — from the loan amount, the monthly interest rate and the number of monthly payments.

Why does a shorter term save so much interest?

Interest accrues on the outstanding balance every month. A shorter term repays that balance faster, so there are fewer months of interest to pay — a higher monthly cost, but a much lower lifetime cost.

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