Enter the amount, the rate and the term to see the monthly payment, what the loan costs in total, and how the balance falls year by year.
Every instalment is the same size. Early payments are mostly interest.
This is arithmetic on the numbers you enter, not a quote. A real contract costs more — see what is left out, below the result.
Monthly payment
| Repayment system | First payment | Last payment | Total interest |
|---|
Fixed principal pays less interest overall; fixed payment starts cheaper. Which one fits depends on circumstances this calculator does not know.
| Year | Principal | Interest | Balance |
|---|
A loan payment is not a slice of the debt. Each month the lender first charges interest on what is still owed, and only what remains of the payment reduces the balance. Early on the balance is at its largest, so the interest is too — in the first year of a 30-year mortgage, around four fifths of every payment is interest and the debt barely moves.
That is also why overpaying early is worth far more than overpaying late. A payment made in year one removes interest that would have been charged on that amount for the following 29 years; the same payment in year 28 saves almost nothing.
Fixed payment keeps every instalment identical, which makes budgeting simple and is the default almost everywhere outside Brazil and Portugal. Fixed principal repays an equal slice of the debt each month, so the payment starts higher and falls steadily — and because the balance drops faster, the total interest is lower.
Neither is better in the abstract. Fixed principal costs less overall, but the first payments are the largest, and lenders assess affordability against that first payment. This page shows both totals side by side and leaves the choice where it belongs.
The figures here follow from three numbers: the amount, the rate and the term. A real contract has more. Arrangement and valuation fees, life and buildings insurance, and taxes all add to the cost, which is why lenders are required to publish a total cost of credit rather than the interest rate alone.
Long mortgages may also be index-linked, so the balance and the payments move with inflation. Treat the result as the arithmetic of the numbers you entered — useful for comparing scenarios against each other, not as a quote.
With the annuity formula: the payment is the amount borrowed multiplied by i(1+i)ⁿ ÷ ((1+i)ⁿ − 1), where i is the monthly interest rate and n the number of months. Each payment covers the interest accrued that month first, and whatever is left reduces the balance — which is why early payments are almost all interest.
Under fixed payment every instalment is the same size, and the split between interest and principal shifts over time. Under fixed principal you repay the same slice of the balance every month, so the interest — and the payment — falls as the balance shrinks. Fixed principal costs less interest in total; fixed payment starts lower.
Because interest is charged on the outstanding balance every month for the whole term. At 9.5% over 30 years, a loan pays back roughly twice what it borrowed. Shortening the term cuts the total sharply even though it raises the monthly payment.
No. This calculator applies the interest rate you enter and nothing else. A real contract also carries arrangement fees, insurance and taxes, which lenders must disclose as an annual percentage rate of charge. That figure is always higher than the nominal interest rate.
It reduces the amount financed, and every figure scales with it. Putting down 20% of the price cuts the payment and the total interest by 20% at the same rate. It also affects what lenders will offer, since most will not finance the full value of a property.
No. The calculation runs entirely in your browser and there is no server to send anything to. The amounts you type are never transmitted or saved.
See how an amount grows over time, month by month, with regular contributions.
Interest charged only on the original amount, with no interest on interest.
Add, subtract, multiply and divide fractions — exactly, never rounded.
Solve a proportion — with the inverse case the usual formula gets wrong.
What is X% of Y — the everyday percentage, worked out step by step.
Add a percentage to a value, or find the increase between two numbers.