Put Your Betriebskostenabrechnung on the Berlin Range
Type the lines from your own operating-cost statement, with the square metres and months printed on it, and each one lands on the official Berlin range for that cost per square metre and month. The lines above the band are the ones worth asking for the invoices on.
Ranges come from the Berliner Betriebskostenübersicht for billing year 2024, published with the Berliner Mietspiegel 2026 from about 1,700 buildings for cold costs and 1,300 for heating and hot water. Deadlines follow § 556 BGB. Checked on 10 September 2026.
The statement for 2025 arrives between October and the end of December 2026, and this year it is the first one carrying the reformed Grundsteuer. Start with the flat size and months printed on the bill, then add lines one at a time as they appear: property tax, water, waste, caretaker, insurance, lift, and the heating and hot water block. Each line becomes a marker on a horizontal band that shows the Berlin 4/5 range and mean for that cost, so you see at once whether your caretaker line is a normal Berlin caretaker line or double one. Underneath, the tool adds up what you entered against the Berlin mean for the same lines, converts the difference into euros a year for your flat, names the lines above the band with the reason they usually go wrong, and prints the two deadlines that matter: the last day the landlord may still claim a top-up for that billing year, and the twelve months you have from receipt to object in writing.
What the band means
For each cost the Berlin survey reports the mean and the two ends of the range that four buildings in five fall inside. That is the light green band, with the mean as the dark tick. One house in five legitimately sits outside it, so a marker above the band is a reason to ask for the invoice and the distribution key, not proof of an error. A marker more than half again above the top of the band is drawn red, because at that distance the explanation is usually structural: a bundled caretaker contract, an owner insurance in the wrong line, or a repair booked as servicing.
How your number is calculated
The tool divides the euro amount you type by the square metres and the number of months on the statement, which gives the same unit the Berlin table uses. If the statement covers a partial year, enter the months it actually covers. Use the square metres printed on the bill rather than the ones in your head; when they differ from the contract, that difference is itself the first finding.
The two deadlines
The landlord must deliver the statement by the end of the twelfth month after the billing period closes, so a calendar-year 2025 bill has to arrive by 31 December 2026 or the top-up is lost. You have twelve months from the day the statement reaches you to raise written objections. The tool prints the first date from the billing year you choose; the second one runs from receipt, so note the day it arrived.
What it cannot tell you
It compares your lines with Berlin averages, not with your own building, and it cannot see whether a line is named in your rental contract, whether several buildings are billed as one unit, or how vacant flats were handled. Those questions are answered in the file review, and the article linked here explains how to ask for it and what to look for.