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: -