If you want to know whether your rent is reasonable, start with the rent index (Mietspiegel). It shows what is usual for comparable flats in your city and provides the benchmark for rent increases and the rent brake. This guide explains where to find the rent index, how to read it and where its limits lie. More housing topics are in our housing guide for students.
In short: A rent index is an overview of the local comparative rent (ortsübliche Vergleichsmiete), drawn up or recognised by the competent authority or jointly by landlord and tenant associations (section 558c (1) BGB). Municipalities with more than 50,000 inhabitants must produce and publish one. You usually find it on your city’s website. Last updated: November 2026.
Key points
- The rent index states the local comparative rent, that is the usual rent for comparable housing.
- It is supposed to be adjusted to market developments every two years.
- Rent indexes and their amendments must be published, usually by the city.
- It is the benchmark for rent increases under section 558 BGB and for the rent brake under section 556d BGB.
- Different rules apply to social housing and dormitories.
What is a rent index and who produces it?
Under section 558c (1) BGB a rent index is an overview of the local comparative rent. The precondition is that the authority competent under state law, or landlord and tenant associations jointly, have drawn it up or recognised it. It can apply to one municipality, several municipalities or parts of a municipality (section 558c (2) BGB).
The local comparative rent itself results under section 558 (2) BGB from the usual rents of the last six years for comparable housing in the municipality or a comparable one. Type, size, fittings, condition, location and energy performance are taken into account.
The law also knows the qualified rent index (section 558d BGB). It is drawn up according to recognised scientific principles. A statutory presumption applies to it that the rents it states reflect the local comparative rent. Whether an index is qualified is usually stated in the foreword or on the title page.
Where do you find the rent index of your city?
Rent indexes and their amendments must be published (section 558c (4) BGB). For municipalities with more than 50,000 inhabitants they must be produced; for smaller ones the authorities are to produce them if there is a need and the effort is reasonable. If none exists for your town, other means of justification come into question.
- On your city’s website, usually under housing, building or housing office.
- At the local tenants’ association, which often has the index as a booklet or download.
- At your university or student services, which give guidance on local rents.
- At the town hall or citizens’ office, where a printed copy is available.
Pay attention to the reference date. Every rent index states a year of publication and the date the data were collected. A rent index is supposed to be adjusted every two years (section 558c (3) BGB), so check whether a newer edition exists for your city. Which reference date applies for your city is stated in the publication itself.
How do you read a rent index?
Most rent indexes work with tables in which rent per square metre is classified by features. Typical entries are:
| Feature | Meaning | What to watch |
|---|---|---|
| Floor area | Size class of the flat | Small flats often have higher prices per square metre |
| Year of construction or age class | Age of the building | After modernisation another class may fit |
| Fittings | Heating, bathroom, flooring, kitchen | Surcharges and deductions according to the list in the index |
| Location | Residential area, district, street | Simple, medium and good locations are often listed separately |
| Range and mean | Lower and upper value, mean | Placement within the range follows the features |
Assumption: for a 40 square metre flat in a medium location built in 1990, the table gives a range of 9.00 to 11.50 euros per square metre with a mean of 10.20 euros. You pay 520 euros excluding utilities, that is 13.00 euros per square metre. This is above the upper value of the range. Whether that is permitted depends on whether the index applies at all, whether special fittings justify the classification, and whether the case is a new tenancy or an increase.
What do you need the rent index for in practice?
For a rent increase under section 558 BGB, the landlord may go at most up to the local comparative rent. With the rent index you check whether the requested rent is within the range. The rules are in the article rent increases for a shared-flat room.
Under the rent brake, rent at the start of a tenancy may be at most 10 percent above the local comparative rent (section 556d (1) BGB) if the flat is in an area covered by a state ordinance. The benchmark is again the rent index. Which exceptions exist is shown in rent brake and new builds, whether it applies to a shared-flat room in Does the rent brake apply to shared-flat rooms?.
Where does the rent index reach its limits?
- Housing whose rent is fixed by law or because of a subsidy commitment is not covered by the local comparative rent under section 558 (2) BGB.
- For student and youth dormitories the rules on rent at the start of a tenancy and on rent increases do not apply under section 549 (3) BGB.
- Many rent indexes cover whole flats. Whether and how single rooms in shared flats are covered is stated in the explanation of the respective index.
- Furnished flats or rooms in the landlord’s own flat can be subject to special rules.
- A rent index is an aid, not a judgment: in a dispute, in the end a court decides.
Frequently asked questions
Must every city have a rent index?
For municipalities with more than 50,000 inhabitants production is mandatory under section 558c (4) BGB. For smaller ones they are to be produced if there is a need and the effort is reasonable.
How current must a rent index be?
It is supposed to be adjusted to market developments every two years. The law words this as a target rule. The year of publication is stated in the document.
Is the middle of the range the rent I must pay?
No. The mean is a guide value. Surcharges and deductions for fittings and location shift the placement within the range.
Does the rent index also apply to existing rents?
Yes, for rent increases under section 558 BGB it reflects the local comparative rent. For the rent brake it applies to the start of the tenancy.
What applies if there is no rent index?
Then the landlord can justify a rent increase request by other means, for example an expert opinion or comparable flats (section 558a BGB). The benchmark remains the local comparative rent under section 558 (2) BGB. You can have the details checked before you agree.
Who helps me interpret it?
Tenants’ associations and university advice services. The article tenants’ association for students (in German) shows when membership is worthwhile.
What to do now
- Look for your city’s rent index on the city website or at the tenants’ association.
- Note the year of publication, the reference date and whether the index is qualified.
- Classify your flat by size, year of construction, fittings and location.
- Compare your rent per square metre with the range and the mean.
- If the difference is large, ask the landlord in writing and seek advice.
Related guides
- Housing while studying: rent, shared flats, dorms and housing benefit
- Rent brake until 2029: what students need to know
- Rent brake and new builds: which exceptions apply
- Rent increase for a shared-flat room
- Student Tenancy Agreement: What You Should Check Before Signing
Sources: Section 558c BGB, rent index, Gesetze im Internet (in German); Section 558 BGB, rent increases up to the local comparative rent, Gesetze im Internet (in German); Section 556d BGB, permitted rent at the start of a tenancy, Gesetze im Internet (in German).
Last updated: November 2026. This guide is general information, not individual advice.
