What is Impuesto a las Ganancias?
The Impuesto a las Ganancias (income tax) on employment taxes remuneration above the non-taxable minimum (mínimo no imponible). The employer acts as withholding agent and deducts it on the payslip.
The amount depends on personal deductions (spouse, children, rent, etc.) and is updated several times a year, so it varies widely between workers.
In practice
A salary above the non-taxable minimum has a Ganancias withholding on the payslip, calculated after applying the personal deductions declared.