The present invention relates to a method for determining the position of at least one rock reinforcing bolt in a tunnel or a mine, with the bolt installation being arranged to be carried out by means of a drilling rig, with the said drilling rig comprising at least one boom with a first end and a second end, with the said first end being attached to a carrier via at least one articulated connection, and with the said boom being arranged to carry an installation tool. The method comprises the steps of determining a position of the said carrier using means arranged on the drilling rig, determining at least one angle of rotation for the said boom in relation to the carrier by determination of an angle of rotation for the said articulated connection, and determining the position of the rock reinforcing bolt in the tunnel or mine on the basis of the said position of the carrier and the said determined angle of rotation. The invention also relates to an arrangement.