Density is calculated on the basis of the number of people per unit area. In order to properly calculate density, the measurements need to match how the space is actually used. Thus, how people space themselves could be dependent on the nature of the egress component. This study compares different methods of calculating densities for people descending stairs based on the different components (treads and landings or just landings) that are observed. The densities on the different components are not found to be equivalent unless factors (adjusted tread depth and adjusted landing area) are applied. When these factors are applied to a second data set that had a different tread configuration, the densities are again equivalent. When the results are applied to a stair where cultural factors could alter the findings, the adjusted landing area needs to be adjusted in accordance with the expected change in behavior. Copyright © 2013 John Wiley & Sons, Ltd.