Template and method for measuring the cross section of a graft

A template for measuring the cross section of a graft comprises a first half-body and a second half-body. The two half-bodies are mutually secured such that they can rotate the one with respect to the other around an axis, each one of the two half-bodies comprises a plurality of openings having known and different sizes, each one of the openings of the two half-bodies is open toward the outside through an at least partially radial slot. The two half-bodies can rotate the one with respect to the other around the axis between an open position and a closed position and vice versa. In the open position the slots of the first half-body axially coincide with the slots of the second half-body, and in the closed position the openings of the first half-body axially coincide with the openings of the second half-body.