Investment property calculator: cash flow and IRR
Cash flow, IRR, and ROI on your Czech property — with mortgage, taxes, and exit after N years.
What counts as a buy-to-let in Czechia?
A buy-to-let is a flat bought to rent out, not to live in. For a mortgage on it the ČNB has recommended, since 1 April 2026, LTV at most 70 % and DTI 7, so a CZK 5 million flat needs at least CZK 1.5 million of your own money. Rent is taxed under § 9 with actual expenses or a 30 % flat-rate deduction.
Gross yield on a Prague 2+kk
Assumption: a 55 m² flat for about CZK 8.0 million (CZK 146,000–150,000 per m², new build in Prague, Q2 2026) let at 2026 Prague rents for a 2+kk.
| Rent CZK 20,000 a month | 3.0 % a year |
|---|---|
| Rent CZK 23,000 a month | 3.45 % a year |
| Rent CZK 26,000 a month | 3.9 % a year |
These are gross figures, before the SVJ fund, insurance, empty months and tax. How banks lend on such a flat is covered in buy-to-let mortgage.
Investment parameters
Price, mortgage, rent, horizon — results update instantly.
15 % is the individual standard — on the difference between rent minus deductible expenses. 0 % for specific exemptions. 21 % for s.r.o. (LLC) and similar.
Results
Cash flow by year
Income, expenses and net cash flow year by year. Property value and your equity.
| Year | Income | Costs | Cash flow | Value | Equity |
|---|
Czech investment property — full breakdown
This calculator simulates your buy-to-let investment year by year and computes the metrics that matter for an actual decision: IRR (internal rate of return), ROI, year-by-year cash flow, and net proceeds at exit.
What is IRR and why it matters
Internal Rate of Return is the annual return on your invested capital after accounting for all cash flows in time. If IRR > mortgage rate, leverage is working for you — borrowed money is earning more than you pay for it. If IRR > 7–8 %, it's a strong investment in current Czech context.
What's included in cash flow
- Income: rent (with annual growth) minus vacancy (5 %)
- Operating costs: SVJ/maintenance (your input), property tax (your input in CZK a year, default CZK 1,150), maintenance reserve (1 % annual)
- Property tax (daň z nemovitých věcí): charged on floor area, not on the price (Act No. 338/1992 Coll.). The default of CZK 1,150 a year fits a 60 m² flat in a Prague apartment building: 60 m² × 1.22 × CZK 3.50 × 4.5, before the inflation coefficient and any local coefficient. If you know your actual tax, enter it in the calculator.
- Mortgage: interest and principal, computed monthly
- Income tax: 15 % on (rent − costs − mortgage interest)
- At exit: sale price − 3 % fees − capital gains tax (if applicable) − mortgage payoff
Capital gains tax — when it's 0 %
In Czech Republic, the sale of a property is exempt from income tax if either:
- You lived in it for at least 2 years immediately before sale, or
- You owned it for at least 10 years (since 2021; previously 5 years), or
- You use the proceeds for your own housing by the end of the year after the sale (and notify the tax office)
Otherwise, the gain (sale price − purchase price − documented costs) is taxed at 15 % for individuals.
What people ask most
What's a good IRR for property investment in Czech Republic?
In current Czech Republic, 6–8 % is good, 8 %+ is excellent. If IRR < 5 %, the investment doesn't beat the average equity market (S&P 500 historically gives ~8 %). If IRR > mortgage rate (~5 %), leverage is working — borrowed money is earning more than you pay for it.
How do banks treat investment mortgages?
Since 1 April 2026 the ČNB has recommended, without making it binding, LTV at most 70 % and DTI 7 for buy-to-let loans, so expect to put in about 30 % of the price yourself. Banks usually count rental income only in part, and for a flat not yet let only once you show a lease. Each bank applies the recommendation its own way, so ask more than one.
What's vacancy and why include it?
Vacancy = the time the property sits empty (between tenants, repairs, seasonal). Realistically 5–10 % per year. If you don't account for it, your real return will be that much lower than the calculation suggests.
What if property prices fall after 5 years?
If you sell during a downturn, you lose the appreciation portion of your return (the calculator assumes constant growth). Rental cash flow continues, partially offsetting. For a sensitivity check, set "0 % appreciation" and see the result without capital gains.
Can I deduct mortgage interest from tax?
Not as an owner-occupier: the deduction of up to CZK 150,000 a year applies only to your own home, not to a let flat. Against rental income (§ 9) the interest counts as an expense if you claim actual expenses; with the 30 % flat rate it is already covered and cannot be added on top. This calculator deducts it when it works out the tax each year.
What's better — flat-rate, actual expenses, or LLC structure?
For rental: 30 % flat-rate (simple, but excludes mortgage interest from deductions) or actual expenses. With high-interest mortgage, actual usually wins. For larger portfolios, an s.r.o. (LLC) at 21 % corporate tax can save money. Consult a tax advisor before your first filing.
How realistic is 3 % annual property appreciation?
It is a cautious planning figure, not a forecast. Year-on-year changes swing widely: in Q2 2026 older flats sold for 14 % more than a year earlier and Prague flats for 11 % more (ČBA), and flat or falling years happen too. For a long horizon, plan with 3 % and test 0 %.