Method for calibrating an automatic pouch forming machine comprising an unwinding unit for unwinding a pouch precursor made of a band of a flexible heat-sealable film in a forward movement direction; a folding unit of the band configured for folding said band in half on itself along at least one folding line parallel to the forward movement direction, a welding unit of the folded band configured for making welding lines at least in a direction transverse to the forward movement direction of the folded band; and a drive unit for moving the band in the forward movement direction; characterised in that the method comprises the steps of: - performing a test operation on the material of the pouch precursor; - performing a characterisation of the material of the pouch precursor based on the results of the testing of the material performed; - conducting a comparison of the characterised material of the pouch precursor with other known materials on which the steps of the test operation and the characterisation have already been performed, said known materials being further related to known operation parameters of a pouch forming machine including welding pressure, welding temperature and welding time; and - automatically adjusting the automatic pouch forming machine with operating parameters, including welding pressure, welding temperature and welding time for the tested material of the pouch precursor, obtained from the result of conducting the comparison and an algorithm treating said results; wherein the step of performing a test operation is performed by: - pressing the band folded on itself of the pouch precursor with a punch, said punch being heatable at least at one tip by a heat source at a given temperature; and - measuring the penetration of the punch in the band folded on itself with a measurement device; and wherein the steps of conducting a comparison and automatically adjusting the automatic pouch forming machine, are implemented by a processing unit. characterised in that the method comprises the steps of: - performing a test operation on the material of the pouch precursor; - performing a characterisation of the material of the pouch precursor based on the results of the testing of the material performed; - conducting a comparison of the characterised material of the pouch precursor with other known materials on which the steps of the test operation and the characterisation have already been performed, said known materials being further related to known operation parameters of a pouch forming machine including welding pressure, welding temperature and welding time; and - automatically adjusting the automatic pouch forming machine with operating parameters, including welding pressure, welding temperature and welding time for the tested material of the pouch precursor, obtained from the result of conducting the comparison and an algorithm treating said results; - performing a test operation on the material of the pouch precursor; - performing a characterisation of the material of the pouch precursor based on the results of the testing of the material performed; - conducting a comparison of the characterised material of the pouch precursor with other known materials on which the steps of the test operation and the characterisation have already been performed, said known materials being further related to known operation parameters of a pouch forming machine including welding pressure, welding temperature and welding time; and - automatically adjusting the automatic pouch forming machine with operating parameters, including welding pressure, welding temperature and welding time for the tested material of the pouch precursor, obtained from the result of conducting the comparison and an algorithm treating said results; wherein the step of performing a test operation is performed by: - pressing the band folded on itself of the pouch precursor with a punch, said punch being heatable at least at one tip by a heat source at a given temperature; and - measuring the penetration of the punch in the band folded on itself with a measurement device; - pressing the band folded on itself of the pouch precursor with a punch, said punch being heatable at least at one tip by a heat source at a given temperature; and - measuring the penetration of the punch in the band folded on itself with a measurement device; and wherein the steps of conducting a comparison and automatically adjusting the automatic pouch forming machine, are implemented by a processing unit.