Simple formulas for calculating the small angle x‐ray scattering from aggregates of identical spherical particles, taking into account the interference between different particles, are given. The case of independent clumps of particles and the case of a more general arrangement describable by a radial density function are considered. Calculated curves of scattered intensityvs.angle for likely arrangements of both types are presented. The assumption that each particle scatters independently is seen to be a poor approximation whenever there is a significant amount of clumping or whenever the average density of the sample is as much as one third of the density corresponding to close packing. Estimates of particle size from the small angle scattering are shown to be seriously affected.