Loan & Mortgage Payment Calculator
A loan or mortgage is usually repaid in equal monthly instalments that cover both interest and a slice of the principal. This calculator applies the standard amortisation formula to turn a loan amount, annual interest rate and term into the monthly payment you can expect, plus the total you will pay over the life of the loan and how much of that is interest.
Enter the amount you plan to borrow, the annual rate your lender quotes, and the term in years. Pick the currency that matches your figures. The result updates instantly and is an estimate for planning — actual offers vary by lender, fees, insurance and your credit profile.
Use it to compare mortgage quotes side by side, to see how a shorter term changes the payment, or to sense-check a refinancing offer before you talk to a lender.
Enter your values to see the result.
How this is calculated
This calculator estimates the fixed monthly payment on a standard amortising loan or mortgage with the formula M = P × r × (1 + r)^n ÷ ((1 + r)^n − 1), where M is the monthly payment, P is the principal you borrow, r is the monthly interest rate (the annual rate divided by 12, as a decimal), and n is the total number of monthly payments (the term in years multiplied by 12). The result is the constant payment that clears both the interest and the principal exactly by the end of the term.
Each payment is split between interest charged on the remaining balance and a reduction of the principal. Because interest is calculated on what you still owe, the interest share is largest in the early years and shrinks as the balance falls, while the principal share grows. The total paid over the term is the monthly payment multiplied by n, and the total interest is that total minus the original principal.
The model assumes a single fixed rate held for the whole term, equal payments starting one month after disbursement, and no fees. It does not include property taxes, home or mortgage insurance, HOA dues, closing costs, origination fees, late charges, variable or teaser rates, balloon payments, or prepayment penalties. Lenders bundle many of these into your real monthly housing cost, so expect the all-in figure to be higher than the principal-and-interest number shown here.
Worked example
Suppose you borrow $250,000 at a 6.5% annual rate for a 30-year term.
- 1Convert the annual rate to a monthly decimal: r = 0.065 ÷ 12 = 0.005417.
- 2Find the number of payments: n = 30 × 12 = 360.
- 3Compute the growth factor: (1 + r)^n = (1.005417)^360 ≈ 7.038.
- 4Apply the formula: M = 250,000 × 0.005417 × 7.038 ÷ (7.038 − 1) ≈ $1,580 per month.
- 5Total paid = 1,580 × 360 = $568,800; total interest = 568,800 − 250,000 = $318,800.
Frequently asked questions
- How is the monthly payment calculated?
- It uses the amortisation formula M = P·r(1+r)ⁿ / ((1+r)ⁿ−1), where P is the principal, r is the monthly interest rate (annual rate ÷ 12) and n is the number of monthly payments. When the rate is zero, it simply divides the principal across the term.
- Does this include taxes and insurance?
- No. The figure covers principal and interest only. Property taxes, home insurance, mortgage insurance and HOA fees are usually added on top by your lender to calculate your full monthly housing cost.
- Why is the total interest so high?
- On a long mortgage most of your early payments go to interest, not principal. Shortening the term or making extra principal payments dramatically reduces the total interest paid.
- How do extra payments change the result?
- Extra payments reduce the principal ahead of schedule, which shrinks the interest charged in every later month and shortens the term. This calculator models a fixed schedule, so it does not show that effect — but even a modest monthly overpayment can cut years off a long mortgage and save a large sum in interest.
- What is APR versus the interest rate I enter?
- The interest rate is the cost of borrowing the principal. APR bundles in certain fees and expresses the true yearly cost, so it is usually slightly higher. For the monthly payment itself, use the interest rate; for comparing total loan cost between lenders, compare APRs.
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Method: standard fixed-rate amortisation formula. No external data source. Last updated: September 2026.
These results are indicative estimates for planning only and do not constitute financial advice. Actual loan terms, tax rules, investment returns and product conditions vary by country, provider and your personal circumstances. Always confirm figures with your bank, tax authority or a qualified financial adviser before making decisions.