NASA TLX: Task Load Index

** PLEASE NOTE- This website is available as a historical reference for NASA TLX. Email support for the NASA TLX tool is not available through this website. **

Welcome to the NASA-TLX homepage. NASA-TLX is a subjective workload assessment tool. NASA-TLX allows users to perform subjective workload assessments on operator(s) working with various human-machine systems. NASA-TLX is a multi-dimensional rating procedure that derives an overall workload score based on a weighted average of ratings on six subscales.

These subscales include Mental Demands, Physical Demands, Temporal Demands, Own Performance, Effort and Frustration. It can be used to assess workload in various human-machine environments such as aircraft cockpits, command, control, and communication (C3) workstations; supervisory and process control environments; simulations and laboratory tests.

NASA-TLX is available for download in two formats. It is available here in its original paper and pencil format and as a fully automated computer application. Data collection may be performed manually or through your computer's keyboard or mouse. For a full review of the features and functions of NASA-TLX, please consult the users' manuals available through the tabs above.

Using the tools made available to you on this site, you will learn how to use the NASA TLX tool. You will also have full access to all TLX-related publications, which will allow you to see how the tool has been applied in a variety of research applications. If you use the tool and would like to add to our publications database, you will also be able to submit your publication to the site.