Measuring the workload that people experience is important, because subjective workload has an impact on human performance. A high workload eats into our limited mental resources and can lead to errors, near-misses and incidents. Workload is often measured by the resources available (such as nurse-to-patient staffing ratios), but workload is experienced differently by different people. For example, two nurses assigned to the same number of patients in the same Intensive Care Unit may experience workload differently due to the stability and complexity of their patients. Therefore, a subjective measure of workload can provide helpful insights beyond traditional measures such as staffing ratios. One of the most common measures of subjective workload developed by the NASA Human Performance Group is now available as an App and can be applied in any industry.