A miter gauge and saw blade calibrator is in the form of a flat plate with grooves defined in top and bottom surfaces at various angles. The grooves are sized to receive the bar of a miter gauge so that bar can be elevated above a table slot with its side extending above the slot abutting a side of the groove. The calibrator is slid along the bar toward the miter head until the miter head lays flat against one of the sides of the calibrator on both sides of the bar, to set the angle between the head and the bar equal to the angle between the groove and the corresponding side of the calibrator. Fine angle calibration bars can also be provided between the calibrator and the miter head so as to set smaller or unusual angle increments. In addition, the perimetral edges of the calibrator form different angles so that one edge can be placed against the table top surface of a table saw or other tool and another edge against the blade to accurately set the angle of the blade. Fine angle calibration bars can also be used for this purpose.