Abstract: Particulate detergent compositions containing a detergent active system, sodium carbonate and a calcite seed crystal exhibit improved dispensibility from automatic washing machines when the mean particle size is at least 500 microns, such as above 700 microns and the level of particles with a size below 50 microns is less than 2% by weight of the overall composition. The Rosin-Rammler distribution n value should be at least 4 when the means particle size is 700 microns but may be as low as 2 when the mean is 1200 microns. When the sodium carbonate and calcite are in separate particles, the sizes thereof should be similar.