In the 1960s Marshall and Hoare presented a "Standard Cooling Curve" based on their mathematical analyses on the postmortem cooling of bodies. Although fairly accurate under standard conditions, the "curve" or formula is based on the assumption that the ambience temperature is constant and that the temperature at death is known. Also, Marshall and Hoare's formula expresses the temperature as a function of time, and not vice versa, the latter being the problem most often encountered by forensic scientists. A simple BASIC program that enables solving of Marshall and Hoare's equation for the postmortem cooling of bodies is presented. It is proposed that by having a computer program that solves the equation, giving the length of the cooling period in response to a certain rectal temperature, and which allows easy comparison of multiple solutions, the uncertainties related to ambience temperature and temperature at death can be quantified, substantiating estimations of time of death.