Commensuration-the transformation of different qualities into a common metric-has recently received increased scholarly attention. While mostly studied at the meso- or macroscale, this article extends the focus to microscale commensuration. Based on fieldwork in a Norwegian emergency medical service, the article analyses how nurses rated patients' pain intensity on a scale from zero to ten. While nurses were instructed to score pain by combining patients' self-report with their own 'objective' assessment, the article finds that their actual assessments relied almost solely on the latter. After exploring nurses' objections against the use of self-report, the article reconstructs the principles, methods and beliefs underlying nurses' 'objective' approach to pain scoring. In so doing, the article demonstrates how a fundamental aspect of human experience was filtered through nurses' professional gaze-to the advantage of some patients and the disadvantage of others. The article also advances theorising on microscale commensuration, thus providing guidance for future studies of how the world is transformed through the everyday production of numbers.