This standard is applied to determine the fiber content (Cf) in fiber reinforced concrete (HRF) samples. The proposed method is applicable in HRF in fresh state and in hardened state. The fibers used to reinforce the concrete must contain steel (or another metallic material with a magnetic permeability greater than that of the concrete) in sufficient quantity to generate a variation in inductance (”L) when a magnetic field is applied. The method is applicable for cubic and cylindrical geometries of fiber reinforced concrete samples.