Mortgage calculator for an investment flat
The mortgage payment, the interest you will pay, the cash you need saved (deposit and the purchase costs of your region) and whether the rent covers the payment.
What will you pay and how much do you need?
Repayment loan: the same payment every month. Purchase costs with the resale transfer tax of your region.
| Loan | €126,000 |
| Monthly payment | €598 |
| First-year interest (deductible if you let it) | €3,733 |
| Interest over 25 years | €53,252 |
| Total you repay to the bank | €179,252 |
| Deposit | €54,000 |
| Purchase costs (transfer tax, notary, registry…) | €13,050 |
| Cash you need saved | €67,050 |
Before the running costs of the flat and income tax: for the real cash flow, open it in the full calculator.
Indicative estimate. Not financial or tax advice.
Next: the full study of your flat
Does it pay for itself with a mortgage?
The same flat bought outright and with different financing: how much you put in, what it leaves you each month and at what interest rate it stops paying for itself.
What a full study looks like
The analysis of a flat from start to finish: detailed taxes, a 10-year projection, sale scenarios, sensitivity and the IRR. With these figures:
- IRR over 10 years
- 11.5%
- Monthly cash flow
- €169
- Net yield
- 5.3%
Find flats that already pay
Draw a circle on the map and we rank the flats for sale in the area by return, with the estimated rent of each one based on the rents around it.
How a mortgage payment is calculated
With the French (repayment) system, the usual one in Spain, you pay the same amount every month. At first it is almost all interest and little by little more of it repays the loan. The payment depends on the amount, the rate and the term: a longer term means a lower payment but more interest overall.
Payment = loan × i ÷ (1 − (1 + i)^−n), where i is the monthly interest rate (annual rate ÷ 12) and n the number of payments.
How much the bank lends if it is not your main home
For a second home or an investment flat, Spanish banks usually lend 60% to 70% of the value (the lower of the valuation and the purchase price) and ask that all your debt payments stay below 30–35% of your income. 80% is possible with a strong profile.
The cash you need
The deposit (what the bank does not lend) and all the purchase costs: the transfer tax of your region or VAT, notary, land registry, agency and valuation. The bank has paid the costs of setting up the mortgage since 2019. Work out the purchase costs.
Does the rent cover the payment?
Rent higher than the payment is not enough: there are still service charges, property tax, insurance, maintenance, empty months and income tax. As a quick rule, look for rent that covers the payment with a margin, for example 1.3 times or more. For the real numbers, open it in the mortgage calculator.
Fixed, variable or mixed
With a fixed rate you always know what you will pay; with a variable rate, the payment moves with Euribor. If it is variable, try one or two points more interest above: if the rent still covers the payment, you have a margin.
Interest in your rental income tax
If you let the flat, the mortgage interest (not the part that repays the loan) is deducted in your rental income tax. Work out that tax.
Reviewed on 10 October 2026
Frequently asked questions
How much do Spanish banks lend for an investment flat?
Usually between 60% and 70% of the value (the lower of the valuation and the purchase price); 80% with a strong profile.
How much cash do I need to buy a flat with a mortgage?
The deposit (what the bank does not lend) and the purchase costs (transfer tax or VAT, notary, registry…): with 80% financed, around 30% of the price.
How is a mortgage payment calculated?
With the repayment loan formula: payment = loan × i ÷ (1 − (1 + i)^−n), where i is the monthly interest rate (annual rate ÷ 12) and n the number of payments.
Is a fixed or variable mortgage better for investing?
With a fixed rate you know your payment and your return from day one; with a variable rate you may pay less or more depending on Euribor. If the flat only pays for itself at today's rate, a fixed rate gives peace of mind.
Is mortgage interest on a let flat tax-deductible?
Yes: in the rental income tax you deduct the mortgage interest and costs, up to what you collect in the year (together with repairs).
Indicative estimate. Not financial or tax advice.