Index-Linked Rent Calculator 2026 by Rechnerzentrale

Current monthly rent

Usually the base rent excluding utilities – service charges stay out of the calculation.

Base month under the contract

Comparison month

You can also drag the chart

Enter your own valuesConsumer price index for Germany, base 2020 = 100. Enter your own values if your contract names an earlier month or a different index base.

Check the deadlines24 months since the last change · notice not yet received

Months since the tenancy started or the rent last changed

Month the increase notice was received

New monthly rent

€955.13

Your rent rises from €800.00 to €955.13 – €155.13 more per month, €1,861.56 per year (index 19.39%).

Consumer price index for Germany (Destatis, 2020 = 100). Dashed: base month. Drag the chart to choose the comparison month.

Previous rent: €800.00
Increase: + €155.13
New monthly rent: €955.13

Index change: 19.39%
Extra cost per 12 months: €1,861.56
Adjustment factor: 1.1939

Legal checkpoints

Twelve-month rule met: the rent has been unchanged for at least 12 months (Section 557b (2) German Civil Code).
The change must be declared in text form and state both the index change that occurred and the new rent or the amount of the increase (Section 557b (3) German Civil Code).
Alongside an index-linked rent, an increase up to the local reference rent under Section 558 German Civil Code is excluded; increases for modernisation and operating costs under Sections 559 to 560 remain possible.

How this was calculated

New rent = current rent × index of the comparison month ÷ index of the base month

€800.00 × 125.6 ÷ 105.2 = €955.13

The calculator implements the formula of Section 557b German Civil Code. Whether the index-rent clause is valid and which base month applies follows from your tenancy agreement – seek legal advice if in doubt.

Index-Linked Rent Calculator 2026 by Rechnerzentrale(opens in a new tab)2026 values