Cranial capacity was measured in Korean adult skulls. The cavity was filled with rice seeds and the volume of the seeds were measured in a graduated cylinder. The results were 1470 +/- 107 (mean +/- standard deviation) in male and 1317 +/- 117 cc in female skulls. These values were in good accordance with those previously reported. In addition, regression formulae were obtained with the product of the length, breadth, and height of the skull as an independent parameter and the measured capacity as a dependent one. With known external measurements, the expected cranial capacity was as follows: when using baso-bregmatic height, male: capacity = 307.5 + 333 x 10(-6) x (length.breadth.baso-bregmatic height) female: capacity = -12.0 + 435 x 10(-6) x (length.breadth.baso-bregmatic height) and, when using auriculo-bregmatic height, male: capacity = 214.6 + 429 x 10(-6) x (length.breadth.auriculo-bregmatic height) female: capacity = 131.6 + 461 x 10(-6) x (length.breadth.auriculo-bregmatic height).