The taper less than 10 degree can be calculated by a simple formula, and the slope x2= taper, the slope =D-d/LX28.7, where d is the diameter of the big end, d is the diameter of the small end, l is the taper length, and 28.7 is the coefficient.

When the taper is greater than 10 degree, the inclination can be calculated by trigonometric function. The inclination of the rotation angle of the small tool holder is equal to the difference between the reduced diameter of the large diameter divided by 2 times the length. The calculated value is found in the tangent value of the trigonometric function table, and the corresponding angle is the rotation degree of the small tool rest.