A grinding machine for grinding a surface of an object is described which has a plurality of grinding brushes which are rotatably mounted about a brush axis of rotation, at least one brush carrier on which at least one of the grinding brushes is mounted and which is rotatably mounted about a carrier axis of rotation, and a conveying device for conveying the object at a feed speed through the grinding machine. The grinding machine has an input device and an output device. A brush rotational speed about the brush axis of rotation and/or a carrier rotational speed about the carrier axis of rotation and/or the feed speed is/are adjustable by the input device, and an expected grinding result can be output by the output device.