Operating Cost Calculator (Nebenkosten)

This calculator estimates your share of a building's operating costs (Nebenkosten) using the living-area key, the default distribution method under the German Operating Costs Ordinance (BetrKV), and reconciles it against your advance payments.

Most tenants pay a monthly advance towards operating costs, and once a year the landlord settles the actual costs against those payments. This tool helps you sanity-check that annual statement before you accept a refund or a back payment.

Under the BetrKV, and unless your contract says otherwise, allocable costs are split by living area: your share is your flat's area divided by the building's total area. The calculator applies that key to the building's total to estimate your portion.

There is an important exception. Heating and hot water must, by law, be split mostly by actual consumption (50 to 70 percent), so for those items the area-based result is only an approximation; the rest is allocated by area.

Comparing your estimated share with what you paid in advance shows whether you can expect a refund (you prepaid more than your share) or a back payment (you prepaid less).

One deadline is worth knowing: the landlord must deliver the operating-cost statement within twelve months of the end of the billing period, after which back payments can usually no longer be demanded. It is an estimate, not legal advice, and runs in your browser.