To facilitate further research in emergent turn-taking, we propose a metric for evaluating the extent to which agents take turns using a shared resource. Our measure reports a turn-taking value for a particular time and a particular time scale, or ‘resolution,’ in a way that matches intuition. We describe how to evaluate the results of simulations where turn-taking may or may not be present and analyse the apparent turn-taking that could be observed between random independent agents. We illustrate the use of our turn-taking metric by reinterpreting previous work on turn-taking in emergent communication and by analysing a recorded human conversation.