Start from the employee file
CNAS payroll calculation does not start with a rate. It starts with a clean employee file: contract, salary, entry date, work schedule, position, company, establishment, RIB, NIN and applicable payroll items.
Monthly variables then complete the file: absences, overtime, bonuses, salary reminders, advances, leave, entry or exit during the month. These variables must be collected, validated and kept before payroll is calculated.
The full guide is available here: CNAS payroll calculation Algeria 2026.
Calculation chain
A reliable payroll run follows a stable order:
- Determine monthly gross pay.
- Identify items subject to CNAS.
- Calculate the CNAS contribution base.
- Calculate employee and employer contributions.
- Determine the salary IRG base.
- Calculate salary IRG using DGI rules.
- Deduct advances or authorized deductions.
- Obtain net pay.
- Produce employer cost and the accounting entry.
CNAS general rate
CNAS states that, in the general case, the contribution rate is 34.5%: 25% borne by the employer, 9% borne by the employee and 0.5% of gross payroll for social works.
Special categories and employer-share abatements may apply. DZ Compta must therefore keep the rate, effective period, reason and supporting reference, then reconcile the result with social contributions, payslips and salary IRG.
Official references
Control the calculation chain
Keep a settings sheet for each payroll item. A bonus or allowance should never be used before its CNAS, IRG and accounting treatment is clear.