Maximum Mortgage Under ČNB Rules

Because it's the only one of ČNB's three mortgage indicators — LTV, DTI, DSTI — that's still legally binding. DSTI stopped being enforceable on 1 July 2023 and DTI on 1 January 2024, both by explicit ČNB decision. LTV was left untouched throughout: 80% generally, 90% for applicants under 36 buying to live in the property. Many mortgage guides still describe DTI and DSTI as strict limits — that hasn't been accurate for over two years.

Because ČNB still publishes them as a non-binding recommendation for what it calls 'highly prudent' credit assessment — 8× annual income for DTI (7× for investment property), 40% of income for DSTI, stress-tested at plus 2 percentage points. Individual banks are free to apply similar thresholds in their own internal scoring even though nothing in law requires them to. We show both figures clearly labelled as a recommendation, never as a legal limit, so you can see where a cautious bank might land.

ČNB's rule applies the 90% cap to 'applicants under 36' buying a home to live in themselves, but the published rules don't specify what happens when co-applicants have different ages. We conservatively use the age of the older applicant, which matches common banking practice — but this is our interpretation, not something ČNB has spelled out. If you're right at the edge of 36, it's worth confirming directly with the bank.

Not really as a matter of right. Banks are allowed to exceed the LTV cap on up to 5% of the loan volume they issue each calendar quarter, but that's a portfolio-level allowance the bank manages across all its borrowers — not an entitlement any individual applicant can invoke. Some banks may choose to use part of that room for a strong applicant close to the cap; that's entirely at the bank's discretion, not something this calculator can predict.

ČNB recommends banks apply a lower 70% LTV and a stricter 7× DTI to loans for investment (buy-to-let) properties, in effect from 1 April 2026 at the latest. It was announced in November 2025 alongside confirmation that DTI and DSTI remain deactivated more broadly. Like the general DTI/DSTI thresholds, this investment-property guidance is a recommendation, not a legally binding measure — but it signals banks are expected to be more cautious on investment lending than on a home you'll live in yourself.

Your actual rate — the one you enter, or our market-average default — shows what you'd really pay each month. A second, higher 'stress' rate, your rate plus 2 percentage points, is used only to work out the DSTI recommendation, because ČNB recommends banks check affordability at a higher rate in case rates rise later. You'd never actually be asked to pay at the stress rate; it's purely a checking tool, not a real payment.

No. This calculator applies ČNB's published limits and recommendations to the numbers you enter — it doesn't run a credit check, doesn't know your credit history or employment situation, and can't see any specific bank's internal scoring model. Individual banks routinely lend less (or, within the LTV cap, sometimes more) than this estimate based on their own assessment. Treat this as a starting point for a conversation with a mortgage advisor or bank, not as a pre-approval.