We present a method for the extrapolation of adiabatic induction times from iso-peribolic experiments. The method requires the knowledge of the heat losses of the reaction system, which are characterized by the Phi-factor and the cooling constant. The base for the extrapolation is the Semenov-theory of explosion. Moreover, two methods were tested, which allow; to differentiate between reactions of nth order and autocatalytic reactions. The computed data of the adiabatic induction periodes are in good agreement with adiabatic experimental data and computed data from the literature. The method of extrapolation provides essential data with respect to safety problems and is also a base for the comparison of experimental results from different measurement devices.