You know the assumed loan instalment and other payments for a potential investment flat. Now you want to know which monthly income would cover this calculation. Such a coverage threshold is a useful internal figure. It is neither an admissible rent nor proof that someone would actually pay that amount.
Define the scope of the calculation
Record only those expenses that would actually be borne by the owner for the specific consideration, and mark allocations that are not yet clarified. The article does not decide on pass-onability (Umlagefähigkeit) or tax deductibility. Financing, property payments and personally desired additional reserves are named as separate items.
Note whether you want to examine a typical plan month or an annual average. Irregular expenses may appear in a smoothed view; their actual payment dates remain available in an additional liquidity view.
The hypothetical threshold case
Assume a €700 loan instalment, €120 other monthly payments permanently borne by the owner in this example, and a separately chosen additional reserve of €80. Together these amount to €900 required monthly income if, under these assumptions, exactly these three items are to be covered.
The €80 is not a professionally recommended reserve level. Taxes, purchase costs, changes in value and other unmentioned items are not represented in this limited example. The calculation is therefore not a full yield model.
Compare the available income
If the actually clarified monthly available income were €820, €80 would be missing under the same assumptions. At €900 the calculation defined here would be balanced. At €950 €50 would remain after exactly these items.
None of these lines allows you to simply change an existing contract to the computationally desired value. Legal admissibility, actual rentability and existing agreements must be checked independently. A higher rent expected by the seller is not used as confirmed income merely because the financing requires it.
Derive the decision from the gap
If there is a shortfall, ask whether you would consciously carry it from actually available other funds and could do so. Also examine the consequences of missing income or additional expenses. A zero result in the base month does not automatically provide sufficient protection against these changes.
This is how the coverage threshold becomes an internal control metric: it shows which income your own assumptions require. It alone does not decide whether a purchase would make sense. A large gap in particular between this and the actually documented income is a reason to further check the assumptions, rather than inventing the rent to fit the table.