Personal taxation · Luxembourg
Tax deductions calculator: effect on your 2025 tax
This tool measures the difference under the 2025 tax scale between two adjusted taxable bases. The reduction you enter must be additional, already classified and net of the flat-rate allowances or deductions included in the initial base. The tool does not decide whether an expense is deductible.
Financial Services Luxembourg · Licensed accountant · Head of the firm: Mickaël LOC. Editorial update: .
Effect of an additional reduction of the base
Tax year 2025 only. Enter the amounts according to the method and scope explained on this page.
Local calculation, with no account and no amounts transmitted. The contact form is separate. Reloading the page clears your entries.
A comparison on the same data
The engine uses the 2025 tax scale for tax classes 1 and 2 and its rounding rules. It compares the tax before and after the reduction, then displays the difference. It does not simply multiply all expenses by the marginal rate displayed.
Tax credits, extraordinary income, tax treaties and tax class 1a are excluded. A reduction that would change these items requires a full calculation outside the scope.
The input must be a net figure
A contribution of EUR 3,200 does not necessarily correspond to EUR 3,200 of additional reduction. You need to check eligibility, the shared or individual ceiling, the flat-rate allowances and what has already been deducted.
An initial base that has already been reduced must not receive the same deduction a second time. If these items have not been checked, the result must remain “review required”.
Fictitious example and scope
A base of EUR 60,000 can be compared with EUR 57,000 if an additional reduction of EUR 3,000 has actually been allowed. The difference in tax is a tax effect limited to this assumption, not a refund or the return on a contract.
Amounts withheld or paid in advance are not entered. They would be needed to estimate the final balance, together with the other excluded items.
Privacy
The calculation runs in your browser, with no account and no transmission of the amounts. The contact request is independent of the result. No simulation amount is added to measurement events or to the public form.
The firm’s other tax engagements
Depending on your situation, the firm also handles tax, VAT and payroll, the regularisation of late tax filings and assistance during a tax audit. Fees are listed in the firm’s fee grid.
Official sources and scope
The rules apply to the year and profile concerned. Examples flagged as fictitious explain a method; they are not an individual validation. The documents and options of your file are covered by a separate engagement.