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Mortgage Calculator online

Calculate monthly mortgage payments and total interest cost

⚠ Not financial advice. Figures are estimates and do not include lender fees, insurance, taxes, or potential rate changes over the life of the mortgage. For general information only — consult a qualified mortgage adviser before making borrowing decisions. See Terms.
Mortgage Calculator logo
by
CHUNKY
MUNSTER

How to Use the Mortgage Calculator

  1. Enter the property's purchase price into Loan amount, then how much you're putting down into Down payment.
  2. Type the lender's quoted APR (annual percentage rate) into Annual interest rate.
  3. Set the Loan term in years — 25 and 30 are the most common fixed-rate terms.
  4. Click Calculate to see the monthly payment, total interest paid over the life of the loan, and total cost of credit.

The maths is the standard amortising-loan formula M = P · r(1+r)^n / ((1+r)^n − 1), where P is the financed amount (loan amount minus down payment), r is the monthly interest rate (APR ÷ 12) and n is the number of monthly payments (years × 12). Total interest is simply M × n − P, and total cost is M × n. The figures are deliberately just principal and interest — the part of the payment that pays down the loan itself — so you can see how rate and term changes move the number without escrow or PMI muddying the picture.

How the Mortgage Calculator Works

This is a baseline P&I estimator: it does not include property tax, homeowners insurance, PMI/MIP, HOA dues, lender origination fees, points, or per-diem interest at closing — those typically add 15–35% on top of the P&I figure. Use it to compare scenarios (10% vs 20% down, 25 vs 30 years, 6.5% vs 7.0%), then ask the lender for an itemised loan estimate for the actual at-closing number. Figures are estimates only and not financial advice.

Frequently Asked Questions

Does this figure include tax, insurance and HOA?

No. The number you see is principal and interest only (P&I). Property tax, homeowners insurance, PMI/MIP and HOA dues are not modelled — add roughly 1–2% of the home value per year as a rule-of-thumb escrow estimate.

Which formula is used for the monthly payment?

The standard amortising-loan formula M = P · r(1+r)^n / ((1+r)^n − 1), where P is the loan after down payment, r is APR/12 and n is the term in months. Total cost is M × n; total interest is M × n − P.

Is the rate assumed fixed for the whole term?

Yes — this is a fixed-rate amortisation. ARMs, interest-only periods, balloon payments and recasts are not modelled. For variable-rate scenarios run multiple calculations at different rates and compare.

Why does my real lender quote differ?

Lender quotes typically include escrow (taxes/insurance), MIP/PMI, origination fees rolled into the loan, and per-diem interest at closing. This calculator gives the pure P&I baseline so you can see how much of the lender's number is the loan itself versus add-ons.

Explore the full suite of Finance tools and 290+ other free utilities at Chunky Munster.

⚠ Disclaimer: This calculator is for informational and educational purposes only. Results are estimates and should not be relied upon as financial, medical, or professional advice. Always consult a qualified professional before making financial or health decisions.