Rent reduction calculator: how much less may you pay?
Enter base rent, service-charge advance, rate and period: the calculator counts every day of the defect separately.
Checked by Radif Partners · Editorial policy · Method
Reduction for the period
€212.77
| Gross rent (basis) | €970 |
| Reduction per full month | €97 |
| Payable in a full month | €873 |
| Days with the defect | 65 |
No statute fixes the rate: it depends on the kind and severity of the defect and, in a dispute, is set by the court. The reduction requires you to report the defect (Section 536c BGB).
How we calculateIf your flat has a defect, German law reduces the rent automatically for as long as the defect impairs its use (Section 536 of the Civil Code); no agreement or court ruling is needed. The reduction (Mietminderung) applies not to the base rent but to the gross rent including the advance or flat rate for service charges, as the Federal Court of Justice decided on 6 April 2005 (XII ZR 225/03). The calculator therefore uses base rent plus service charges and spreads the reduction over every calendar day of the defect, because a 28-day month counts differently from a 31-day one. Example: €750 base rent and €220 advance make €970 gross. At a rate of ten per cent that is €97.00 in a full month; from 10 January to 15 March 2026 it adds up to €212.77. No statute sets the rate itself; it depends on the defect and, in a dispute, is set by the court.
What the calculator does, and what it does not
It turns a reduction rate into euros: gross rent times rate for each full month, and for part months each day with its share. It does not tell you what the rate should be. Section 536 BGB knows three levels only: if the flat cannot be used at all, no rent is owed; if its use is impaired, an appropriately reduced rent is owed; if the impairment is minor, there is no reduction. During the first three months of an energy-saving modernisation a reduction is excluded (Section 536(1a) BGB).
Three conditions before you pay a single euro less
- Report the defect. Under Section 536c BGB you must report a defect without delay. If you do not, you lose the right to reduce as far as the landlord could not fix it because of that. The reporting defects page shows what to include.
- Not a defect you knew of when signing. If you knew of a defect when you signed, you cannot reduce the rent for it; if you take over a defective flat knowing of the defect, you must reserve your rights at the handover (Section 536b BGB).
- Careful with the cut. Rent is due by the third working day (Section 556b BGB). Cut too much and you fall into arrears for the rest. Many tenants therefore keep paying under reservation and reclaim later.
| Step | Amount |
|---|---|
| base rent plus advance | €970.00 |
| rate | 10% |
| reduction in a full month | €97.00 |
| reduction from 10 January to 15 March 2026 (65 days) | €212.77 |
The rent reduction page has more on the conditions and on why no reliable rate table exists.