Method for measuring a tool received in a workpiece processing machine (WSBM) having the steps: • providing a contact or noncontact tool sensing device (WATS, WATE) for detecting positional data on the tool and for outputting signals (S1, S2,... Sn) representative of the positional data, • providing an evaluation device for receiving and processing the signals (S1, S2,... Sn) and for outputting a tool geometry determined from the processed signals; characterised in that the method comprises the following steps: • detecting a sequence of a first number of positional data on the tool, wherein the detecting of the sequence of the first number of positional data on the tool comprises positional data, the sensing positions of which on the tool are specified to lie spaced apart from one another each by 10 μm to 1 mm based on a predetermined sensing position on the tool or along a sensing direction on the tool, and outputting signals (S1, S2,... Sn) representative of said positional data to the evaluation device; • processing the signals (S1, S2,... Sn) representative of the first number of positional data in order to obtain a first approximation of the tool geometry (WZG-N1); • comparing the first number of positional data with said first approximation of the tool geometry (WZG-N1) and excluding a subset of the first number of positional data depending on a predetermined criterion, in order to obtain a second number of positional data; • processing the second number of positional data in order to obtain a second approximation of the tool geometry (WZG-N2); and • outputting said second approximation of the tool geometry (WZG-N2) as the tool geometry determined for the tool. • providing a contact or noncontact tool sensing device (WATS, WATE) for detecting positional data on the tool and for outputting signals (S1, S2,... Sn) representative of the positional data, • providing an evaluation device for receiving and processing the signals (S1, S2,... Sn) and for outputting a tool geometry determined from the processed signals; • detecting a sequence of a first number of positional data on the tool, wherein the detecting of the sequence of the first number of positional data on the tool comprises positional data, the sensing positions of which on the tool are specified to lie spaced apart from one another each by 10 μm to 1 mm based on a predetermined sensing position on the tool or along a sensing direction on the tool, and outputting signals (S1, S2,... Sn) representative of said positional data to the evaluation device; • processing the signals (S1, S2,... Sn) representative of the first number of positional data in order to obtain a first approximation of the tool geometry (WZG-N1); • comparing the first number of positional data with said first approximation of the tool geometry (WZG-N1) and excluding a subset of the first number of positional data depending on a predetermined criterion, in order to obtain a second number of positional data; • processing the second number of positional data in order to obtain a second approximation of the tool geometry (WZG-N2); and • outputting said second approximation of the tool geometry (WZG-N2) as the tool geometry determined for the tool.