NASA-TLX Calculator

NASA Task Load Index: A multi-dimensional tool for assessing workload.

The NASA-TLX assesses workload across six dimensions. Below are the standard definitions with clinical examples.

Mental Demand
How much mental/perceptual activity was required (thinking, deciding, calculating, remembering)?

e.g., Calculating complex drug infusions vs. Routine observation.

Physical Demand
How much physical activity was required (pushing, pulling, turning, controlling)?

e.g., Performing CPR vs. Typing notes.

Temporal Demand
How much time pressure did you feel? Was the pace slow or frantic?

e.g., Managing a chaotic trauma call vs. Elective pre-op assessment.

Performance
How successful were you in accomplishing the goals? How satisfied were you?

Note: Low Score = Good Performance. High Score = Failure.

Effort
How hard did you have to work (mentally and physically) to accomplish your level of performance?

e.g., Working through exhaustion vs. Fresh start.

Frustration
How insecure, discouraged, irritated, stressed and annoyed did you feel?

e.g., Fighting broken equipment vs. Smooth workflow.

Citation: Hart, S. G. and Staveland, L. E. (1988) ‘Development of NASA-TLX (Task Load Index): Results of empirical and theoretical research’, in Hancock, P. A. and Meshkati, N. (eds) Human Mental Workload. Amsterdam: North-Holland, pp. 139–183.

Workload Assessment

This tool consists of two parts:

  1. Weighting: You will compare sources of workload to determine what contributed most to the load.
  2. Rating: You will rate the task on each of the six scales.


Step 1: Sources of Workload

For the task you just performed, which of these two factors contributed more to the workload?

Option A

OR

Option B

Comparison 1 of 15

Step 2: Rating Scales

Click on each scale at the point that best indicates your experience.

Assessment Complete

Raw TLX Score
-

Unweighted Average

Weighted TLX Score
-

Adjusted for personal priorities

Interpretation

Your Weighted Score indicates the overall workload. The "Raw" score is a simple average, while the "Weighted" score accounts for which factors you found most significant.

Dominant Factor: -