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Rent indexation calculator (Belgium)

Free tool based on the Statbel health index and compliant with the Law of 6 August 1993. Covers Wallonia, Brussels and Flanders — with automatic handling of the regional EPC factor.

Single step

A few details.
The exact result.

Property region, lease dates, initial rent, EPC class. The calculation runs instantly.

Property region
€ / month
€
coefficient 100%
Result · real-time
New indexed rent
—€
— —
LEGAL FORMULA APPLIED
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How the calculation works

Rent indexation in Belgium follows a single formula governed by the Law of 6 August 1993 and the Royal Decree of 24 December 1993. It uses the raw health index published monthly by Statbel, which excludes volatile products (alcohol, tobacco, fuel).

Indexed rent = Base rent × (Health index of the month preceding the anniversary date ÷ Health index of the month preceding signature)

Why our calculator displays an EPC factor

Since 2022, two regions have introduced a corrective coefficient based on the energy performance of the property:

  • Brussels (Brussels Housing Code, art. 224/2 § 1er/2): for leases signed before 14 October 2022, the coefficient is 75% for EPC E-F and 0% for G.
  • Flanders (Flemish decree of 4 July 2023): a permanent coefficient applied according to the property's EPC, including for pre-2022 leases.
  • Wallonia: no EPC cap applies any more since 31 October 2023. Standard federal calculation.

Documents to prepare

  • The lease contract (signature date and entry-into-force date)
  • The amount of the initial rent (excluding charges)
  • The property's energy class (EPC, depending on the region)
  • The year for which you are requesting indexation

Dedicated regional calculators

For a calculation pre-filled with the regional legal context, use:

Frequently asked questions

How is rent indexation calculated in Belgium?
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The legal formula is: Indexed rent = Base rent × (Health index of the month preceding the anniversary date ÷ Health index of the month preceding signature). For Brussels and Flanders, an EPC correction factor may apply to leases signed before October 2022.

On which date does indexation take effect?
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On the anniversary date of the lease's entry into force (not the signature date). If your lease entered into force on 1 July 2021, indexation takes effect on each subsequent 1 July.

Which health index should be used?
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The raw health index published by Statbel (not the smoothed health index, which is used for salaries). The calculator automatically selects the correct base year (1988, 1996, 2004, 2013 or 2025) according to the date the lease was signed.

Does the lease need to be registered to apply indexation?
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Yes. The Law of 6 August 1993 conditions the right of indexation on the lease being registered within 2 months of signature. Without registration, indexation is not due and the tenant may legitimately refuse it.

Can I claim several years of forgotten indexation?
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No. Retroactivity is strictly limited to 3 months under Belgian law. Beyond that, the indexable rent is permanently lost for the unclaimed period.

Is the calculator's result legally binding?
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The calculator strictly applies the legal formula with the official Statbel indices. It serves as a reliable reference, but in case of dispute the justice of the peace makes the final ruling (free procedure). Our PDF notification letter is designed to provide all the expected supporting documentation.

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