In response to calls in the Information Systems literature to contextualize usage, we propose that measuring computer-based multitasking is essential to accurately describe and properly assess the manner in which people use Information Technology. To this end, we develop several multitasking metrics ranging from a very lean dichotomous variable to a very rich measure that combines user, task and technology considerations. Our metrics lay the foundation to conduct larger scale studies focused on computer-based multitasking behavior and to use multitasking as a contextual or intervening variable in other research endeavors on IT usage.