A floor grinder (100) for processing a concrete surface (101), the floor grinder comprising one or more rotatable abrasive tool holders (150) arranged in a plane (P) to hold respective abrasive tools (210, 510), at least one power source (110, 120) arranged to drive the tool holders (150), a cover body (130) fixedly arranged in relation to the plane (P), and a dust skirt (140) movably attached around a rim of the cover body (130) to engage the concrete surface (101) during floor grinding operation, where the floor grinder (100) comprises at least one tool wear indicator (160) configured to indicate a current tool wear based on a displacement of the dust skirt (140) relative to the cover body (130) in a direction (D) normal to the plane (P).