A machine tool, in particular a grinding machine, comprising: - a workpiece mount comprising at least one workpiece holder (16, 18) for accommodating a workpiece, - a tool unit comprising a tool spindle, particularly comprising a grinding head, for accommodating and for driving a tool, in particular at least one grinding wheel, wherein the tool unit is movable along a feed axis towards the workpiece, - a measuring device which is accommodated at the tool unit, wherein the measuring device comprises two measuring probes (66, 68), and - a control device, which is connectable to the measuring device and the tool unit, wherein the control device is configured for acquiring values detected by the two measuring probes (66, 68), and for detecting an actual position of the tool unit along the feed axis, wherein - the two measuring probes (66, 68) are spaced apart in a measuring configuration by a basic spacing defining a measurement region, wherein the basic spacing is selected to be greater than a known reference dimension, and - the control device is configured for determining an actual spacing of the workpiece, in particular an actual diameter, on the basis of a displacement path of the tool unit when mutually probing a workpiece that is moved into the measurement region, with the two measuring probes (66, 68) under consideration of the reference dimension and/or the basic spacing, characterized in that the mutual probing comprises an initial probing of the workpiece with a first measuring probe of the two measuring probes (66, 68), which is moved by means of a movement of the tool unit, on which the measuring device is accommodated, along the feed axis until a measurement can be effected and then a probing of an opposite side of the workpiece with the second measuring probe by the tool unit being moved correspondingly along the feed axis. - a workpiece mount comprising at least one workpiece holder (16, 18) for accommodating a workpiece, - a tool unit comprising a tool spindle, particularly comprising a grinding head, for accommodating and for driving a tool, in particular at least one grinding wheel, wherein the tool unit is movable along a feed axis towards the workpiece, - a measuring device which is accommodated at the tool unit, wherein the measuring device comprises two measuring probes (66, 68), and - a control device, which is connectable to the measuring device and the tool unit, wherein the control device is configured for acquiring values detected by the two measuring probes (66, 68), and for detecting an actual position of the tool unit along the feed axis, wherein - the two measuring probes (66, 68) are spaced apart in a measuring configuration by a basic spacing defining a measurement region, wherein the basic spacing is selected to be greater than a known reference dimension, and - the control device is configured for determining an actual spacing of the workpiece, in particular an actual diameter, on the basis of a displacement path of the tool unit when mutually probing a workpiece that is moved into the measurement region, with the two measuring probes (66, 68) under consideration of the reference dimension and/or the basic spacing,