Fixed-rate mortgage calculator
Calculate your monthly payment, total interest and how the outstanding balance evolves (French system).
Outstanding balance and payment split
Total cost composition
- Principal repaid€180,00066%
- Interest€93,19934%
Information, not tax or financial advice.
How the fixed-rate mortgage calculator works
This calculator uses the French amortization system (the standard in Spain): from the principal, the rate and the term it derives your constant monthly payment, the total interest and the amortization schedule. It also estimates the APR including the opening fee and the linked insurance (home, life) the bank requires to grant the rate: that's the honest figure for comparing offers.
How the payment is computed. With principal C, monthly rate i (annual rate ÷ 12) and n months: Payment = C × i / (1 − (1 + i) ^ −n).
Worked example (default values). €180,000 at 3 % nominal over 30 years, with a 0.5 % opening fee and €300/year of linked insurance:
- Monthly payment: €758.89.
- Total interest: about €93,199.
- Total in payments: €273,199 (principal + interest).
- Opening fee: €900; insurance (30 years): €9,000.
- Total cost with fees: €283,099.
- Estimated APR: 3.35 % (above the 3 % nominal because of the fee and insurance).
What the chart reveals. Although the payment is constant, in the early years it's almost all interest; that's why early repayment saves far more sooner than later.
An important nuance. The nominal rate sets the payment but excludes fees and insurance. To compare banks, look at the APR: with the fee and insurance at 0, the APR equals the monthly compounding of the nominal rate (3.04 %); any linked cost pushes it up.