Loan Calculator — payment, interest, schedule

Enter the principal, annual interest rate and term. The monthly payment, total interest and a full amortisation schedule are computed live.

How does loan amortisation work?

A fixed-rate amortising loan splits each monthly payment between interest (the cost of borrowing) and principal (paying down what you owe). Early payments are mostly interest because the balance is large; late payments are mostly principal because the balance has shrunk.

The closed-form formula for the monthly payment is M = P × r × (1+r)^n / ((1+r)^n − 1), where P is the principal, r the monthly interest rate (annual / 12), and n the number of months. This calculator runs that formula directly in your browser — no rounding errors hidden in spreadsheet macros, no values sent to a server.

How to use this tool

Pick your currency, then drag or type the principal you want to borrow.
Set the annual interest rate (the rate your lender quotes — convert from monthly if needed by multiplying by 12).
Choose the term in years. The monthly payment, total cost and total interest update live; click 'Show schedule' to see every payment broken down.

Frequently asked questions

Is this only for mortgages?

No. The same fixed-rate amortisation formula applies to mortgages, car loans, personal loans and most consumer credit. Variable-rate loans, balloon payments and interest-only loans are not modelled here.

What rate should I enter — APR or nominal?

Use the nominal annual rate that your lender uses to compute interest. APR (annual percentage rate) usually includes fees and is meant for comparison shopping, not for cash-flow projection. If your lender quotes only the APR, your actual interest charge may differ slightly.

Are early-repayment fees included?

No. The schedule assumes you pay exactly the regular amount every month. Some loans charge a penalty if you repay early; check your contract before paying down faster than scheduled.

What if my interest is compounded daily, not monthly?

Most consumer loans in Europe and North America use monthly compounding (the formula in this calculator). Daily compounding is more common in some credit lines and savings accounts; the difference for a typical mortgage is under 1% over the full term.

Why does early payment save so much interest?

Because every euro of principal you pay early stops accruing interest for the rest of the term. On a 25-year mortgage, paying down 10% of the principal in year 1 can shave 15-20% off the total interest paid — far more than the same payment in year 20.

Common use cases

Where running a quick amortisation simulation pays off.

Compare mortgage offers

Two banks offer 3.40% over 25 years and 3.55% over 22 years. Plug both into the calculator and compare total interest plus monthly cash-flow impact — sometimes the higher rate over a shorter term costs less overall.

Plan a car purchase

Decide between a 36-month and a 60-month auto loan. The longer term lowers the monthly payment but the schedule shows how much extra interest you'd pay overall.

Decide whether to overpay

Use the schedule to find the principal balance at the end of year 5. Compare to your savings yield — if your investment returns less than your loan rate, paying down early wins.

Refinancing decision

Recompute your remaining months at the new rate. The savings from refinancing usually beat fees once the gap exceeds 1 percentage point on a 200k+ loan.

Tips and shortcuts

Habits that make borrowing decisions easier.

Always look at total interest, not just monthly payment

Doubling the term roughly halves the monthly payment but can more than double the total interest. The schedule's total cost line is the right number to compare across offers.

Round up your payment when you can

Paying €50 extra a month against a €1,200 mortgage payment can shave years off the term. Set up the overpayment as a standing order so you don't have to remember.

Watch the early-repayment clause

European mortgages often cap the early-repayment penalty at 3% of the principal for the first few years, then drop to 0%. Time your big lump-sum payment after the cliff if you can.

Negotiate the rate, not the term

A 0.20 percentage point rate cut on a 25-year mortgage saves roughly the same as switching to a 23-year term — but it doesn't increase your monthly cash-flow obligation. The shorter term forces you to overpay; the lower rate just makes your money work harder.