Mortgage Total Cost Calculator
What this calculator shows
The monthly payment tells you whether a mortgage is affordable; the total cost tells you how much the loan really costs. The calculator uses the standard amortization formula for a fixed-rate loan, multiplies the monthly payment by the number of payments, and subtracts the amount borrowed to get the interest.
Worked example
A €250,000 mortgage at 4% over 25 years:
- Monthly payment: €1,319.59
- Total repaid: 300 × 1,319.59 = €395,878
- Interest: €145,878 — 58% of the amount borrowed
The table displayed with your result shows, year by year, how much capital you repay, how much interest you pay and what you still owe.
Term and rate: what each one costs
| Scenario | Monthly payment | Total interest |
|---|---|---|
| €250,000, 4%, 25 years | €1,319.59 | €145,878 |
| Same loan over 20 years | €1,514.95 | €113,588 |
| Same loan at 3.5%, 25 years | €1,251.56 | €125,468 |
Shortening the term by five years costs €195 more per month but saves more than €32,000 of interest. Half a point of rate is worth about €20,000 over 25 years — worth negotiating or comparing several lenders.
What is not included
- Borrower insurance: often required, it can add thousands to tens of thousands of euros over the life of the loan. In France, the Lemoine law (2022) lets you switch insurer at any time, which can significantly reduce this cost.
- Arrangement and guarantee fees, broker fees.
- Notary or closing costs on the purchase itself.
The annual percentage rate (APR) your lender must provide includes interest, insurance and mandatory fees: it is the figure to compare between offers.
Reducing the total cost
Extra repayments early in the loan are the most effective, because they cut the balance on which interest is calculated. Check whether your contract charges early repayment penalties. The loan payment calculator lets you test monthly budgets; the compound interest calculator shows what the same money could earn if invested instead.
Frequently Asked Questions
Why is the total interest so high?
Interest is charged every month on the outstanding balance for the whole term. Over 25 years, even a moderate rate adds up to a large share of the amount borrowed.
Is it better to shorten the term or lower the rate?
Both help. In the example, 5 years less saves about €32,000 and 0.5 point less saves about €20,000. A shorter term raises the monthly payment, a lower rate reduces it.
Does the result include insurance?
No. It covers capital and interest only. Add borrower insurance and fees, or use the APR quoted by your lender, to get the full cost.