Standard-essential patents (SEPs) have become a key element of technical coordination via standard-setting organizations. Yet, in many cases, it remains unclear whether a declared SEP is truly standard-essential. To date, there is no automated procedure that allows for a scalable and objective assessment of SEP status. This paper introduces a semantics-based method for approximating the standard essentiality of patents. We provide details on the procedure that generates the measure of standard essentiality and present the results of several validation and robustness exercises. We illustrate the measure’s usefulness in estimating the share of true SEPs in firm patent portfolios for several telecommunication standards.