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Výnosometr

Buy-to-let mortgage calculator for Czech property

Rent may cover the mortgage payment without covering every outgoing. Enter the price, deposit, interest rate and rent to estimate the result after costs and tax, and the return including a future sale.

Sample calculation

Does the rental flat add up? Start with an estimate.

Estimate the monthly shortfall or surplus, the return on your equity and how it compares with an ETF.

a month
−CZK 18,104
return a year
7.9%
Rating
Investment with caveats
Result ↓

Inputs

Where is the flat and what is the price?

CZK
m²

How much will you contribute towards the price?

default. A model assumption, not a verified figure for your flat. You can change it.
%

You contribute CZK 1,580,000 towards the price; the model finances the remaining CZK 6,320,000 with a mortgage.

How will you rent it out?

A residential tenancy rather than accommodation sold by the night.

What rent will you get?

CZK / mo.

Indicative rent for Prague: CZK 20,800 (462 CZK/m²). This is based on city asking rents; check comparable flats.

The model uses a 5.1% mortgage rate, payments of CZK 3,825 a month (including CZK 2,250 of services paid by the tenant while occupied), a sale after 10 years and estimated tax.

Values marked ≈ come from market data, your other inputs or model assumptions. Check them and adjust where needed.

Results

Investment with caveats. Monthly cash flow: −CZK 18,104.

Example
Investment with caveats

A return of 7.9% a year falls short of the 8% target, in a pessimistic scenario the return drops to 0.9%, you also pay interest and costs out of pocket (CZK 8,526 a month on top of principal).

Every month
−CZK 18,104
you top up in year 1, 10-year average −CZK 14,119
Annual return on your money
7.9%
, 0.9% in a pessimistic scenario
Versus over 10 years
+CZK 837,188
more than an ETF at 6%
How we rated it0 of 3 checks passed
  • Return ()7.9%

    target at least 8%, below 4% red

  • Resilience: return in a pessimistic scenario0.9%

    target at least 4% (IRR), below 0% red. Pessimistic scenario: price growth 2.0%, rate after fixation 6.1%, 11 occupied months a year.

  • Cost coverage−CZK 8,526

    CZK 8,526 a month short of running costs, interest and taxes

  • Why these thresholds →
A loan of 80% of the price exceeds the 's 70% guidance for investment mortgages. The lender also uses its own collateral valuation. Check financing availability.
The model is at the 10-year holding-period boundary. Check the actual dates and other exemption conditions before selling.

What could improve the rating

How the deposit changes the result

DepositLoanMonthly paymentFirst-year monthly resultAnnualised return on invested cash (IRR)Model rating
20% (1,580,000 CZK)6,320,000 CZK34,314 CZK−18,104 CZK7.9%investment with caveats
30% (2,370,000 CZK)5,530,000 CZK30,025 CZK−13,815 CZK7.4%investment with caveats
40% (3,160,000 CZK)4,740,000 CZK25,736 CZK−9,525 CZK7.1%investment with caveats
50% (3,950,000 CZK)3,950,000 CZK21,447 CZK−5,236 CZK6.8%investment with caveats

The example uses a 45 m² flat in Prague, a price of 7,900,000 CZK, and the existing rent and interest rate of 5.1%. It compares financing options for the same investment. IRR includes the assumed sale rather than rental income alone.

A larger deposit reduces the loan and payment. Its effect on the percentage return also depends on interest, income and the future property price. Borrowing can amplify losses as well as gains.

From 1 April 2026, the Czech National Bank recommends that lenders apply a maximum LTV of 70% and DTI of 7 to investment mortgages. LTV compares borrowing with collateral value; DTI compares total debt with annual net income. The lender assesses each application and uses its own valuation. A 20% deposit scenario illustrates sensitivity, not an available mortgage offer.

At the end of the fixed-rate period

Rate after fixed-rate periodMonthly result after rate resetWhole-investment IRR
5.1%−9,065 CZK7.4%
6.1%−12,116 CZK6.9%
7.1%−15,306 CZK6.4%

Scenario with a 30% deposit and a 5-year fixed-rate period. The monthly result is the average for the first year after the fixed-rate period, not a promised monthly payment.

Test higher and lower rates. Also change rent and the repair reserve: adverse changes can happen together. Read the Czech buy-to-let mortgage guide for financing conditions.

Frequently asked questions

How much of a deposit do I need?

It depends on the valuation, lender and your circumstances. The CNB's investment-mortgage guidance uses a maximum LTV of 70%. Allow for transaction costs and a reserve as well as the difference between price and borrowing.

Is it enough for rent to cover the mortgage payment?

No. Rent also has to cover owner costs, vacancy, repairs and any tax. Assess the monthly result after those items.

What happens when the fixed-rate period ends?

A new interest rate is agreed for the next fixed period. A higher rate can increase payments and reduce cash flow. You can change the post-fix rate in advanced mode.

Example: Every month−CZK 18,104Return 7.9%