Mortgage calculator (annuity installments)
How Polish banks calculate your installment
Almost every mortgage in Poland is repaid in monthly installments calculated with the annuity formula: M = P x r x (1+r)n / ((1+r)n - 1), where P is the loan amount, r is the monthly interest rate (the annual rate divided by 12) and n is the number of monthly installments. The result is one equal payment that quietly shifts its internal proportions over time: at the beginning most of it is interest, and towards the end most of it is principal.
Polish banks let you choose between two repayment schedules:
| Feature | Annuity (equal) installments | Decreasing installments |
|---|---|---|
| Monthly payment | The same every month (for a given rate) | Starts higher, falls every month |
| Total interest paid | Higher over the loan life | Lower over the loan life |
| Required creditworthiness | Lower - assessed on the equal installment | Higher - assessed on the larger first installments |
| Best for | Most borrowers; predictable budgeting | Borrowers with a comfortable income buffer |
Most borrowers in Poland - including foreigners - choose annuity installments, which is why this calculator models them. If your creditworthiness comfortably exceeds the loan amount, decreasing installments are worth discussing, because they cut the total interest bill.
What actually drives your interest rate
The rate you type into the calculator is a sum of two parts. The first is the reference rate - for variable-rate loans this is currently based on WIBOR, which is being reformed and is due to be replaced by a new index by the end of 2027. The second is the bank's margin, which is fixed in your contract and is the part you can negotiate. As of 2026, the margin a bank offers depends mainly on:
- Your down payment - the regulatory minimum is 20% of the property value (or 10% with low-down-payment insurance), and a higher down payment usually means a lower margin. Foreigners without permanent residence are often asked for 20-30% - see the full guide for foreigners.
- Cross-selling - banks lower the margin in exchange for a personal account with salary inflow, a credit card or insurance bought through the bank.
- Your income profile - a stable employment contract in PLN gets the best treatment; B2B income typically needs 12-24 months of history; foreign-currency income narrows the choice of banks considerably.
- Rate type - instead of a variable rate you can take a rate fixed for 5 years, which every bank must have in its offer; it prices in stability, so compare both variants.
Look at the APRC (RRSO), not just the rate
Two offers with the same interest rate can differ by tens of thousands of zloty over the loan life. That is because the rate ignores the bank's commission (typically 0-3%), compulsory insurance, the property valuation fee and other costs. Polish law requires every offer to state the RRSO - the Polish name for the APRC (Annual Percentage Rate of Charge) - which rolls all mandatory costs into one comparable percentage. When you compare offers, rank them by APRC and by the total repayment amount, never by the headline rate alone. A full breakdown of one-off purchase costs - tax, notary, court fees - is in the costs and taxes guide.
From an estimate to a real credit decision
The calculator answers one question: "what would the installment be for a given loan?". It deliberately does not answer the harder question: "how much will a bank actually lend me?". That depends on your income type, existing liabilities, household size, residence status and each bank's internal policy - and the answer can differ by 30-40% between banks for exactly the same client. Before you sign a preliminary purchase agreement (see the buying property in Poland guide), have your real borrowing capacity verified against current bank criteria. I do this free of charge, in English, comparing 20+ Polish banks - the bank pays my fee, so you pay the same price as going directly.
Frequently asked questions
How is the installment calculated?
What interest rate should I assume in 2026?
Annuity vs decreasing installments - which should I choose?
Does the calculator show my creditworthiness?
More answers for foreign buyers in the full FAQ.
Related guides
- Mortgage in Poland for foreigners Requirements, documents, timeline
- Mortgage for non-EU citizens Residence cards, Blue Card, MSWiA permit
- Mortgage for EU citizens The simpler path, differences vs non-EU
- Buying property in Poland Notary, land register, step by step
- Costs & taxes PCC, notary fees, commissions, down payment
- FAQ All common questions in one place
Turn the estimate into a real offer - for free
The calculator shows the math; I show you which of 20+ Polish banks will actually approve you and at what conditions. My service costs you nothing - the bank pays my fee, and you pay the same price as going directly.