Mortgage calculator: how much can I borrow?

What you can borrow for a home in Czechia is the lowest of a few limits. The ČNB, the Czech central bank, caps the loan at a share of the home's value, so your savings set one limit. Your bank checks that you can afford the payments, so your income sets another. For a flat bought to let, the ČNB adds a third: all your debt against your income. The calculator works out each limit, shows which one stops you, and turns the loan into the price of the home it buys.

How to use the calculator

The calculator answers two questions. Pick one at the top, under "What do you want to know?".

1. What can I afford? starts from your money. Put in the household's net income a month, the payments your other loans already take, and the savings you can put in. The calculator returns the largest loan and the price it buys.
2. What will it cost a month? starts from a home. Put in the price and your down payment to see the monthly payment, the interest over the term and what you'd still owe each year.

Then tell it who's buying. "What it's for" switches between your own home and a flat to let, which brings in the ČNB's stricter limits. Tick "I'm under 36" if you're under 36 and buying your own home. Buying with someone older? Ask the bank how it applies the age.

Under "The mortgage" set the interest rate and the term. The rate starts at the ČNB's latest average for new housing loans. Replace it with your bank's offer once you have one. A longer term lowers the payment and raises the interest you pay in all.

Reading the result

In budget mode the result leads with two figures:

• Borrow up to is the largest loan, rounded down to the thousand.
• Homes up to is the price that loan buys, once your savings, after the purchase costs, pay the rest.

Below them, "What each limit lets you borrow" lists the loan your income allows, the loan your savings allow and, for a flat to let, the ČNB's debt limit. The one marked "Sets the limit" is the lowest, and the sentence under the result says why. That's the line to read twice: it tells you what would raise your budget. If your income sets the limit, saving more won't help much, but paying off a car loan might. If your savings set it, every crown you add to your savings lets the bank lend several more, up to the income limit.

In payment mode you get the monthly payment, the mortgage, its share of the price (loan to value), the interest over the term, the total repaid and the cash you need on day one. The chart shows what you still owe year by year. The table splits each year's payments into interest and repayment. Early on, most of each payment is interest.

At the bottom, the calculator counts the flats for sale on Bytky that ask no more than your budget, by layout, across Czechia or in a place you pick. Each count opens the map with those flats.

A worked example

A household takes home 60,000 Kč a month, has no other loans and has saved 1,500,000 Kč. They want a home to live in, over a 30-year term. Say their bank offers 5 % (your own rate will differ).

• The income limit. 45 % of 60,000 Kč is a payment of 27,000 Kč a month. At 5 % over 30 years, that payment repays a loan of 5,029,000 Kč.
• The savings limit. The purchase costs, a 2,000 Kč cadastre fee and about 15,000 Kč for a lawyer, leave 1,483,000 Kč. As 20 % of a price, that would buy a home of 7,415,000 Kč with a loan of 5,932,000 Kč.
• No debt limit, since it's their own home.

The income limit is lower, so they could borrow 5,029,000 Kč and buy a home of up to 6,512,000 Kč, borrowing 77 % of its price.

Now switch to "What will it cost a month?" with a price of 6,500,000 Kč and 1,300,000 Kč down. The mortgage is 5,200,000 Kč, exactly the 80 % a bank may lend. The payment is 27,915 Kč a month. Over 30 years they'd pay 4,849,165 Kč in interest on top of the loan. On day one they need 1,317,000 Kč: the down payment and the purchase costs. For that payment to be 45 % of their income, a bank would want to see about 62,000 Kč a month, a little more than they earn.

Prices decide how far a budget goes. This is the median asking price per m² of two-room flats in Prague, with the middle half of asking prices as a band:

The rules behind the limits

Loan to value. The ČNB's binding limit lets a bank lend at most 80 % of the value of the home the loan is secured on, or 90 % to applicants under 36 buying their own home. The ČNB left it unchanged in June 2026.¹ The value is the bank's valuer's figure, which can come in below the price.

A flat to let. Since 1 April 2026 the ČNB recommends that a mortgage on a flat bought to let, or on a third or further home, lends at most 70 % of its value, and that all your debt stays within seven times your net income for a year.² These are recommendations rather than binding limits, but banks follow them.

Payments against income. The ČNB capped all loan payments at 45 % of net income (50 % under 36) from April 2022 until it lifted the cap on 1 July 2023.³ Banks still test affordability, each its own way, often with their own estimate of a household's living costs. The calculator uses 45 % as a typical ceiling. Lower it if you'd rather keep a margin.

Purchase costs. Czechia abolished the property transfer tax in 2020. What's left is the cadastre fee of 2,000 Kč to enter you in the land register⁴ and a lawyer for the contract and the escrow of the price. Banks also charge for the valuation, and some for the loan itself.

Tax relief. Interest on a mortgage for your own home lowers your income tax base, by up to 150,000 Kč of interest a year for loans from 2021.⁵ The mortgage calculator leaves it out. The rent or buy calculator counts it.

Mistakes people make

• Counting gross income. The limits work on what the household takes home after tax and insurance.
• Putting all your savings into the down payment. The purchase costs, the move and the first furniture come out of the same savings. Leave a reserve.
• Assuming the price is the value. If the valuation comes in below the price, the bank lends its share of the lower figure, and the gap comes from your savings.
• Reading the rate as fixed for 30 years. It's fixed for the fixation, usually a few years. When it ends, the rate is set again, and you can repay or move the loan without a fee.
• Counting on the under-36 limit as a couple where one is older. Banks apply the age their own way. Ask before you plan on borrowing 90 %.
• Stopping at the bank's maximum. A payment at 45 % of your income leaves little room for a child, a lost job or a higher rate after the fixation.

What to do next

Run rent or buy with the same home to see whether buying beats renting over the years you'd stay. Our guides cover what buying a flat costs, the steps of a purchase and getting a mortgage as a foreigner. Before you make an offer, check the asking price against similar flats nearby with the price check.

Sources

1. ČNB, binding limits for mortgage loans: LTV at most 80 %, 90 % for applicants under 36 buying their own home; left unchanged on 4 June 2026. ↩

2. ČNB recommendation from 1 April 2026 for investment mortgages: LTV at most 70 %, total debt at most 7 times net annual income. ↩

3. ČNB, press release on lifting the DSTI limit from 1 July 2023 (cnb.cz). ↩

4. Administrative Fees Act (634/2004 Coll.), item 120: 2,000 Kč for an entry in the land register (ČÚZK). ↩

5. Income Tax Act (586/1992 Coll.) §15(3)–(4): up to 150,000 Kč of interest a year for loans from 2021, 300,000 Kč for older ones. ↩