1. Direct costs
Costs that arise directly from the employee's absence
☐ Gross salary of the sick employee
You pay an average of 30 days' salary for short-term absences – even without any productivity in return.
☐ Employer's social security contributions during illness
Social security contributions continue to run, even when the employee is absent – an average of 25% on top of the gross salary.
☐ Guaranteed salary (first month)
Employers bear the full cost in the first month of illness, especially in the case of stress-related absence such as burnout or depression.
2. Replacement costs
Costs to get the work done anyway.
☐ Hiring a temporary replacement
Temporary employees, freelancers or interims cost an average of 15–30% more per hour than permanent staff.
☐ Overtime or extra workload for colleagues
Team members have to step in, which leads to increased stress levels and the risk of further absences.
☐ Loss of productivity within the team
Research shows that the team works 20–30% less efficiently when a key employee is absent for a long period.
☐ Training or onboarding of replacement
Training a new person takes time from other colleagues, which further increases the indirect cost.
3. Indirect costs
Difficult to measure, but impactful side effects.
☐ Delay of projects or deadlines
Schedules have to be adjusted, which puts pressure on performance and affects customer satisfaction.
☐ Loss of expertise / knowledge loss
Especially with senior profiles: their knowledge is often not easily transferable.
☐ Loss of quality or errors
Stress, time pressure and understaffing lead more quickly to errors or missed opportunities.
☐ Customer dissatisfaction or damage to image
Unexpected delays or communication problems due to the absence of key employees can cause reputational damage.
4. Organizational costs
Time and energy costs for HR and managers.
☐ Time spent by HR or managers
An average of 2–6 hours of administration, follow-up, and consultation per absent employee per month.
☐ Administrative follow-up and planning adjustments
Contract management, sick notes, return-to-work plans, back-up tasks...
☐ Legal risks in the event of long-term absence
Absence files require a correct approach and communication. Mistakes can lead to sanctions or conflicts.
5. Psychological and cultural impact
Effect on the team and the working atmosphere.
☐ Morale dip among colleagues
Teams under constant pressure more often experience frustration, fatigue or reduced engagement.
☐ Contagion effect: 2nd wave of absence
Absence of one employee increases the risk of absence of others in the team due to extra workload or negativity.
☐ Loss of trust in policy or leadership
If there is no structural solution, faith in HR or management initiatives decreases.
6. Missed opportunities
What you miss by putting out fires instead of building.
☐ Stalled innovation or improvement projects
HR or team leaders have less time for strategic work when absence management takes priority.
☐ Delay in culture, well-being or DEI projects
Projects that really connect and motivate employees are too often left on the shelf.
☐ Loss of employer branding
High absenteeism is noticed internally and externally – which undermines recruitment power and retention.
Recommendation
Have HR, finance and management go through this checklist together. Each box checked is a hidden cost. Add them up, and consider: What does doing nothing cost?
Would you like concrete ideas to reduce these costs for your organization? Schedule a short wellbeing review session, and we will look at the possibilities together.
Sources:
Belgian labor legislation, 2025
Health survey IDEWE, 2022.
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