Your financial situation
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How do Czech banks work out how much you can borrow?
Two caps limit a Czech mortgage. The binding ČNB limit: the loan may be at most 80 % of the property value, 90 % under 36. The banks' internal limit: all debt payments usually up to 45 % of net income, 50 % under 36. On CZK 60,000 net that allows a payment of about CZK 27,000 and a loan of about CZK 5.0 million over 30 years; a couple on CZK 100,000 reaches about CZK 8.4 million.
Which income counts and what banks deduct is explained in how Czech banks count your income. The calculator above runs the Czech National Bank's LTV limit and the banks' DSTI and DTI thresholds together and shows which one stops you first.
The ČNB limit and banks' internal rules
- LTV (Loan-to-Value) — max. 80 % of property value (90 % if you're under 36)
- DSTI (Debt Service to Income) — total monthly debt payments ≤ 45 % of net income (50 % under 36)
- DTI (Debt to Income) — total debt ≤ 8.5× annual net income (9.5× under 36)
For a typical borrower (60k Kč net, no other debts, 30-year term, 5 % rate), DSTI tends to allow about 5.0M, DTI 6.1M, and LTV depends on the property — so often LTV is the bottleneck if you don't have a 20 % down payment.
Frequently asked questions
What income do I need for a 5 million Kč mortgage?
Roughly 55,000–65,000 Kč net per month, depending on your existing obligations. The exact number depends on the rate, term, and any other debts (which are deducted from your DSTI capacity).
What counts toward DSTI?
All your debt service: the new mortgage payment, plus existing loans, credit card minimums (banks even count unused credit-card limits!), car leases, alimony. Pay off small debts and cancel unused credit cards before applying.
Will the bank lend more if I'm under 36?
Yes, significantly. If at least one applicant is under 36, the ČNB allows LTV 90 % (vs. 80 %), and banks' internal DSTI and DTI thresholds are usually looser too (for example 50 % vs. 45 % and 9.5× vs. 8.5×). On CZK 60,000 net at 5.00 % over 30 years, the payment cap rises from about CZK 27,000 to CZK 30,000, which means a loan of about CZK 5.6 million instead of 5.0 million.
How does the bank calculate income for self-employed (OSVČ)?
Banks work from your last 1–2 tax returns, usually from the tax base (income minus expenses). If you claim flat-rate expenses (paušální výdaje) or pay the flat-rate tax (paušální daň), many banks count a fixed share of your turnover instead. Each bank has its own formula, so the same return can give different results at two banks.
Are ČNB limits binding or just recommendations?
Only LTV is binding (80 %, or 90 % for under-36s). The ČNB deactivated DSTI on 1 July 2023 and DTI on 1 January 2024; since then neither is a ČNB limit, and the ČNB only advises extra caution above DTI 8. Banks keep their own internal thresholds, which usually resemble the old limits, so plan with them. From 1 April 2026 the ČNB also recommends stricter parameters for investment mortgages (third and further property, or a flat bought to let): LTV 70 % and DTI 7.
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