April 17, 2026
How Much Should an Apartment Really Cost? Worked Examples by Apartment Size
Instead of a single blanket number, a concrete calculation by apartment size helps you judge whether a rental listing is fair or overpriced. As a baseline, we use the nationwide average operating-cost figure of €2.28 per square metre a month (Deutscher Mieterbund), combined with different Kaltmiete levels.
One-room apartment (30-35 sqm)
At an average Kaltmiete of €9 per square metre (a mid-sized city), a 32-square-metre apartment works out to:
Kaltmiete: approx. €288
Nebenkosten advance payment: approx. €73
Warmmiete total: approx. €361
In one of Germany's seven biggest cities, Kaltmiete for the same floor area tends to run €14 to €18 per square metre instead, pushing Warmmiete up to €520-€650.
Two-room apartment (55-60 sqm)
For a 58-square-metre apartment at a mid-range rent level of €10 per square metre:
Kaltmiete: approx. €580
Nebenkosten advance payment: approx. €132
Warmmiete total: approx. €712
In sought-after parts of the top-7 cities, Kaltmiete of €900 to over €1,200 for the same size isn't unusual, pushing Warmmiete up to €1,050-€1,400.
Three-room apartment (80-90 sqm), roughly family-sized
Kaltmiete (€10/sqm, 85 sqm): approx. €850
Nebenkosten advance payment: approx. €194
Warmmiete total: approx. €1,044
How to quickly size up a listing
Divide the Kaltmiete quoted in the listing by the floor area in square metres. If the result sits well above the local rent index (Mietspiegel — usually available online through the city administration or the local tenants' association), it's worth checking more closely whether the rent is genuinely in line with the market or potentially breaches rent-control rules (Mietpreisbremse). The same logic applies to the Nebenkosten advance payment: if it's noticeably above €2.87 per square metre (the Mieterbund's upper benchmark for every permitted cost category combined), treat that as a warning sign that the flat fee has been set too high. Our rental cost breakdown explains how Kaltmiete, Nebenkosten, and Warmmiete relate to one another in the first place, and our guide to checking your Nebenkostenabrechnung covers what to do once the annual statement actually arrives.
Frequently Asked Questions
How do I calculate whether a rent is reasonable?
Divide the Kaltmiete by the square metre count and compare the result with the local Mietspiegel. A deviation of more than 20 percent above that benchmark can, in tight housing markets, even breach the Mietpreisbremse.
How high should the Nebenkosten advance payment realistically be?
Somewhere between €2.28 (the average) and €2.87 (the upper benchmark when every permitted cost is passed on) per square metre a month, depending on the building's age and energy standard.
Why does Warmmiete matter more than Kaltmiete for budgeting?
Because Warmmiete is the actual amount that leaves your account every month. Kaltmiete alone tells you nothing about your total monthly cost unless you add the Nebenkosten on top.
Do costs per square metre differ a lot between small and large apartments?
Yes. Smaller apartments often carry a higher Kaltmiete per square metre than larger ones, because the bathroom, kitchen, and connections generate fixed costs regardless of the apartment's overall size.
