Binary coal blends of a range of Carboniferous and Cretaceous coals were studied using the loose-pack dilatation (LPD) method developed at CANMET Energy Technology Centre. The data were used to develop equations, based on LPD expansion data and vitrinite reflectance distributions for the component coals, to predict expansions for binary blends. An equation was similarly developed to predict dilatation temperatures (T-1, T-2 and T-3) for such blends. It was also found that the dilatometric behaviour of binary coal blends consisting of high- and low-rank components appeared to be independent of the LPD behaviour and origin of the high-rank component when the blend contained greater than or similar to 70% of the low-rank coal.