Calculation reminder
The best rent indexation calculator depends on your usage. Rent indexation in Belgium follows the health index of the month preceding the lease anniversary. This top 3 compares the tools for calculating indexation quickly and without error.
The official formula: Indexed rent = Base rent x (new health index / reference health index)
Two values to find: the new health index (health index of the month preceding the lease anniversary) and the reference health index (index of the month preceding the lease signature).
1. SPF Finances / Statbel — The free official calculator
The SPF Finances and Statbel offer official calculators using the legal formula with up-to-date health indices. Official tool, reference in case of dispute, free, reliable, covers Wallonia, Brussels and Flanders. Limitations: basic interface, no history, no alerts, no link with the lease.
2. BailBelgique — The integrated automatic calculator
Our platform integrates a rent indexation calculator into lease tracking. Once the lease is created, the tool detects the anniversary date and generates the calculation automatically. Full automation, EPC cap application (decree of 31 October 2023), ready-to-send indexation letter, history per property, annual alerts, multi-lease tracking. 24.90 EUR/month all-inclusive.
3. Excel / spreadsheet — The manual solution
For technical landlords, a custom Excel spreadsheet allows self-calculation. Enter the Statbel health indices and apply the formula. Free and customisable. Limitations: indices must be updated monthly, formula error risk, no EPC cap application, no alerts, no generated letter.
Regional specificities
Wallonia: standard health index. Since the decree of 31 October 2023, EPC caps apply to class E, F, G properties. Indexation is reduced or blocked.
Brussels Capital Region: similar rules with its own EPC caps.
Flanders: applies its own caps since 2022 depending on energy class, different from Walloon and Brussels rules.
BailBelgique applies these regional rules automatically based on the property location.
BailBelgique pricing - Online rental management - Create a lease online.