A sizing caliper for determining the optimum size of a femoral component of a knee prosthesis includes a caliper body, a drill guide body, a stylus tower and a graduated stylus slidably coupled to the stylus tower. The caliper body, the drill guide body and the stylus tower arc slidably linked to each other by a linkage pin laterally extending there through in a manner thereby when the caliper body and the stylus tower are linearly displaced in opposite directions in reference to the drill guide body, the caliper body and the stylus tower are linearly displaced at an equal rate with respect to the drill guide body.
