ESDU Struct 02.01.49 gives graphs from which the buckling stress coefficient of a plate tapered in thickness along its length may be obtained for all four cases of a pair of opposite edges either clamped or simply-supported. A constant uniform compressive load is applied in the direction of the taper. The resulting four graphs give curves of buckling stress coefficient plotted against the aspect ratio of the plate for fixed values of the ratio of the greater to the lesser thickness. Two sets of curves are given, for cases when the plate is either fully constrained against transverse displacement or completely free transversely. The buckling stress coefficient is defined as the stress at buckling non-dimensionalised by the modulus of elasticity of the material and factored by the square of the ratio of the width of the plate to its thickness at the thinner end. The data apply to materials that are isotropic and have a Poisson's ratio of 0.3. It is suggested that the data may be used in the plastic range to provide a conservative result if the modulus of elasticity in the definition of the buckling stress coefficient is replaced by the tangent modulus appropriate to the stress in the thinner end of the plate.