A method and device for computing the heat transferred during the period of time the oven takes to reach a predetermined cooking temperature comprising: at least one processor for estimating a first cooking time; a memory; an input for inputting the first cooking time and the amount of time an oven takes to achieve a series of cooking temperatures; the at least one processor operating to estimate the heat transferred to the food during the time period that the oven takes to reach the predetermined cooking temperature; the at least one processor operating to compute the amount of heat transferred to the food per unit time at the predetermined cooking temperature, and the at least one processor operating to calculate a reduced cooking time needed to cook the food based upon insertion of food into the oven at a temperature other than the predetermined cooking temperature.