The health index and rent indexation in Belgium: full explanation
Understanding the Belgian health index and its role in rent indexation. Calculation formula, difference from the CPI, recent history and practical examples for landlords and tenants.
What is the health index
The health index is a statistical indicator published monthly by the FPS Economy (Statbel). It measures the change in the cost of living in Belgium, but excludes four categories of products considered harmful or volatile: alcohol, tobacco, petrol and diesel.
This index serves as the legal basis for:
- Rent indexation
- Salary indexation
- Social benefit indexation
- Property tax indexation
The legislator chose the health index rather than the consumer price index (CPI) to prevent fuel and tobacco price increases from being automatically passed on to rents and salaries. The health index generally evolves 0.5 to 1% more slowly than the CPI.
For both landlord and tenant, understanding the health index mechanism is essential to verify that rent indexation is correctly calculated. A rental management software automatically integrates the indices to secure the calculation.
The indexation formula based on the health index
The formula is identical in all three Belgian regions:
Indexed rent = base rent x (new health index / base health index)
The parameters in detail
| Parameter | Definition | Where to find it |
|---|---|---|
| Base rent | Initial rent agreed in the lease | The lease contract |
| Base index | Health index of the month preceding the lease signing | statbel.fgov.be |
| New index | Health index of the month preceding the lease anniversary | statbel.fgov.be |
Beware of index bases
The health index has changed base several times (1988 = 100, 1996 = 100, 2004 = 100, 2013 = 100). Older leases refer to a different index base than the one used today. The FPS Economy provides an online conversion tool for leases signed before 2013.
Comparing indices from different bases is the most common calculation error. An index of 180 on the 1988 base is not comparable to an index of 130 on the 2013 base. Always use the same base for the numerator and denominator.
Index smoothing
Since 2024, the health index is published as a smoothed value (average of the last 4 months). This smoothing dampens monthly variations and provides more predictable indexation.
Recent trends in the health index
The 2021-2023 surge
The energy crisis of 2021-2023 caused an exceptional rise in the health index, leading to rent indexations of 8 to 10% over two years. This situation prompted the regions to introduce EPC restrictions to limit indexation on energy-intensive properties.
Trends 2024-2026
| Year | Annual health index change | Average impact on rent |
|---|---|---|
| 2023 | +5.8% | +52 EUR/month for a 900 EUR rent |
| 2024 | +3.2% | +29 EUR/month |
| 2025 | +2.4% | +22 EUR/month |
| 2026 (forecast) | +2.0 to 2.5% | +18 to 22 EUR/month |
Return to normal
After the exceptional years of 2022-2023, the health index is returning to a more moderate rate of progression, close to the ECB’s inflation target (2%). Rent indexations in 2026 will therefore be more contained than in previous years.
To learn the specific indexation rules for 2026, see our detailed article on rent indexation in 2026.
Practical calculation examples
Example 1: recent lease in Brussels
- Lease signed on 1 June 2024, base rent: 950 EUR
- Property EPC: C (indexation authorised in Brussels)
- Health index May 2024 (base 2013): 133.71
- Health index May 2025: 136.92
Calculation: 950 x (136.92 / 133.71) = 972.83 EUR, rounded to 973 EUR
Example 2: older lease in Wallonia
- Lease signed on 1 September 2018, base rent: 750 EUR
- Property EPC: E (full indexation authorised in Wallonia)
- Health index August 2018 (base 2013): 107.62
- Health index August 2025: 136.45
Calculation: 750 x (136.45 / 107.62) = 951.01 EUR, rounded to 951 EUR
Example 3: blocked property in Flanders
- Lease signed on 1 March 2022, base rent: 800 EUR
- Property EPC: G (indexation blocked in Flanders since 2026)
- Result: the rent remains at 800 EUR, regardless of the index evolution
The FPS Economy provides an official simulator on economie.fgov.be that automatically calculates the indexed rent. Always compare your manual calculation with the simulator to avoid errors.
To generate a lease with the correct index base, use our online lease creator.
Conclusion: mastering the index to control your income
The health index is the cornerstone of Belgium’s rent indexation system. Understanding it allows the landlord to secure their rental income and the tenant to verify that indexation is correctly applied.
Key points to remember:
- The health index excludes alcohol, tobacco, petrol and diesel
- The formula is identical in all three regions: base rent x (new index / old index)
- The base index is from the month preceding the signing of the lease
- The index bases (1988, 1996, 2004, 2013) are not interchangeable
- 2026 indexation will be more moderate (2 to 2.5%) after the years of high inflation
To automate the indexation calculation and receive reminders at each anniversary date, discover our rental management platform.
Frequently asked questions
-
The health index is a subset of the consumer price index (CPI) that excludes four product categories: alcohol, tobacco, petrol and diesel. It is therefore generally lower than the CPI. It is this health index that serves as the legal basis for rent indexation in Belgium.
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The health index is published monthly by the FPS Economy on statbel.fgov.be. It is generally available around the 28th of the month for the previous month. Some rental management software automatically integrates the latest indices to facilitate the indexation calculation.
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The base index is the one from the month preceding the month of signing the lease. Example: for a lease signed on 15 March 2023, the base index is that of February 2023. This rule is identical in all three Belgian regions.
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