In intermediate moisture foods polyols are added to decrease the water activity. However, an easily readable diagram for industrial use describing combined effects of different polyols on the final water activity of the food product is, to our knowledge, missing. Therefore, in this study the influence of sorbitol and glycerol on the water activity in the range of 0.6 - 0.8 in monomeric and binary polyol solutions was examined and predicted using combinations of the Raoult, Norrish and Ross equations. A ternary diagram describing the combined effects for the use in confectionery was developed.