Rent brake calculator: is your new rent too high?
Your municipality and start date decide whether the brake applies; the reference rent and the previous rent set the ceiling.
Checked by Radif Partners · Editorial policy · Method
Maximum rent at the start of the tenancy
€453.53
€366.47 too much per month
| Local reference rent | €6.65/m² |
| Reference rent for your floor area | €412.30 |
| Range in the rent index | 5.77–8.74 €/m² |
| Rent brake | applies until 31 December 2029 |
| Increase cap | 15 % in three years |
| Limit: reference rent + 10% | €453.53 |
| Recoverable up to the complaint | €2,931.76 |
| Complaint with full effect until | 1 September 2028 |
You can only reclaim after a written complaint. If it arrives within 30 months of the start and the tenancy is still running, it reaches back to the start (Section 556g(2) BGB).
How we calculateThe rent brake (Mietpreisbremse) caps the rent at the start of a German tenancy at the local reference rent plus 10 per cent, but only in municipalities a state has listed in an ordinance under Section 556d(2) of the Civil Code, and only for leases signed while that ordinance is in force. The calculator checks both against the date of your lease, works out the reference rent from the rent index for Berlin and Hamburg, and applies the exemptions: a higher previous rent, new builds first let after 1 October 2014, and the first letting after a full modernisation. Take a 1910 flat of 72 m² in a good Berlin location. The 2026 index gives €8.97 per square metre, so the lawful rent is €710.42 a month before service charges. At an agreed €980 you overpay €269.58 every month. With a complaint in October 2026 on a lease that began in March 2025, €5,391.60 can be reclaimed, because the complaint comes within 30 months.
What the calculator checks
First the municipality. The rent brake is a federal law that only bites where a state government has found a tight housing market and listed the municipality in an ordinance. The calculator holds the lists of all 16 states with their dates. If your lease was signed before the ordinance took effect or after it expired, Section 556d BGB sets no ceiling. Then the reference rent: worked out from the index in Berlin and Hamburg, taken by you from the city's official rent index elsewhere. Last, the exemptions in Section 556e and Section 556f BGB.
The results appear on the right: the lawful ceiling, how far your rent exceeds it, and, with the date of your complaint, the amount you can reclaim up to then. Section 556g(2) BGB sets the refund period: it reaches back to the start if the complaint arrives within 30 months and the tenancy is still running.
The example step by step
| Step | Value |
|---|---|
| Reference rent, Berlin index 2026, good location, built by 1918, 70 to 80 m² | €8.97 per m² |
| times 72 m² | €645.84 |
| plus 10 per cent | €710.42 |
| agreed net cold rent | €980.00 |
| overpaid per month | €269.58 |
| refund with a complaint on 12 October 2026, lease from 1 March 2025 | €5,391.60 for 20 months |
Rent index values are net cold rents. If your lease includes some service charges in the rent, deduct them first. Furniture surcharges are not part of the index; they are still subject to the rent brake, but no official table sets their level, so the calculator leaves them out.
After the result
If your rent is above the ceiling, the next step is a written complaint; the complaint page lists what it must contain. You can also first ask the landlord for the facts behind the rent (Section 556g(3) BGB). With a graduated rent the ceiling applies to every step, with an index-linked rent only to the starting rent.