Luxembourg bonus and 13th-salary calculator

Transparent marginal impact

Method and limitations

The calculator compares two scenarios from the 2026 gross-to-net engine: ordinary salary alone, then the same salary plus the selected payment. The differences isolate additional net pay, contributions, estimated tax and employer cost.

This annualised comparison is not the exact withholding calculation for the payment month. That depends on ordinary remuneration, semi-net non-periodic pay, tax class, tax-card settings and the monthly social-security ceiling.

Official calculation sources

• CCSS · confirmed

  Employee contribution rates from 1 January 2026

  Accessed on 16/08/2026 · Employee and employer shares, accident, mutual insurance and limits from 1 January.

• CCSS · confirmed

  Contribution bases

  Accessed on 16/08/2026 · Minimum, ceiling, part-time work and dependency allowance.

• Administration des contributions directes · confirmed

  Income tax scales

  Accessed on 16/08/2026 · The tariff effective in 2025 remains the latest official adjustment applicable in 2026.

• Administration des contributions directes · confirmed

  Employee CIS and CO2 tax credits from tax year 2026

  Accessed on 16/08/2026 · 2026 formulas for the employee CIS and CO2 tax credit.

• Administration des contributions directes · confirmed

  Calculating the tax charge on a gratuity

  Accessed on 23/08/2026 · Official example distinguishing ordinary monthly withholding from the non-periodic remuneration scale applicable since 1 January 2025.