The paper provides data on the wing areas of 855 birds of 66 species and wing spans of 918 individuals of 58 species of African raptors. Two measures of wing loading were calculated for those individuals that were weighed. Wing, secondary and ulnar lengths are used to derive an index of wing area which explains 98,8% of the variation in the mean wing areas of 46 species. A regression, derived from this relationship, can be used to estimate wing areas from the three linear measurements, all of which can be taken on museum specimens. Similarly, an index, using the sum of wing and ulnar lengths accounts for 99,5% of the variation in the mean wing spans of 36 species. The wing dimensions of males and females, and adults and juveniles are compared in several species. For those species with adequate samples of measurements of wing area, body mass and wing span, the cost of flapping flight can be estimated with confidence.