RULA Calculator
RULA (Rapid Upper Limb Assessment) screens the postural risk to a worker's upper limbs and gives an action level. Choose the posture that best matches each body segment, add the muscle use and load, and the grand score updates live using the standard McAtamney and Corlett worksheet.
This is a free taste of the full ErgoSphere platform, which can score RULA automatically from markerless motion capture and file the result straight into a project report.
Score the Posture
Group A Arm and Wrist
Assess the working side (or the more loaded side).
Group B Neck, Trunk and Legs
Assess the head, back and lower-body posture.
Muscle Use and Force or Load
Applied to both Group A and Group B scores.
RULA is a screening tool. It supports, but does not replace, a full assessment by a competent person.
What is RULA?
The Rapid Upper Limb Assessment (RULA) is a postural analysis tool developed by Dr Lynn McAtamney and Professor E. Nigel Corlett at the University of Nottingham, first published in Applied Ergonomics in 1993. It evaluates a worker's exposure to the risk factors associated with work-related upper limb disorders.
RULA gives a rapid, systematic assessment of posture, muscle use and force without specialist equipment. You assign scores to each body segment, combine them through lookup tables, and arrive at a single grand score from 1 to 7 that indicates the level of musculoskeletal risk and how urgently it should be acted on. It is especially well suited to seated work, screen-based tasks and upper-limb-intensive assembly.
RULA assesses two segment groups. Group A covers the upper arm, lower arm and wrist; Group B covers the neck, trunk and legs. Each group gives a posture score via a table, which is then modified by muscle use and force or load before a final table combines them into the grand score.
When to use RULA
- Screen workstations for upper-limb musculoskeletal risk
- Evaluate postures in seated, computer-based or assembly work
- Compare risk before and after an ergonomic change
- Prioritise which tasks need a fuller, more detailed assessment
RULA is focused on the upper limbs. For tasks with significant whole-body postures, such as heavy lifting, deep bending or reaching overhead, use REBA (Rapid Entire Body Assessment), which extends the method to the full body with extra coupling and load considerations. For manual lifting specifically, the NIOSH Lifting Equation or Snook Tables are better suited.
Scoring and Action Levels
Each body segment gets a base score from its angle, rising as the posture deviates further from neutral. Adjustments are then added for modifying factors, for example +1 for a raised shoulder or an abducted upper arm, +1 for the wrist deviating from the midline, and +1 each for a twisted or side-bent neck or trunk. Assess one side of the body at a time, choosing the side that is most loaded or at greatest risk.
Muscle use and force or load
After the posture scores come from Tables A and B, two modifiers are added to both groups:
| Modifier | Condition | Added |
|---|---|---|
| Muscle use | Posture mainly static (held over 1 minute) or repeated more than 4 times per minute | +1 |
| Force or load | No resistance, or under 2 kg intermittent | +0 |
| 2 to 10 kg intermittent load | +1 | |
| 2 to 10 kg static or repeated load | +2 | |
| Over 10 kg, or sudden or shock forces | +3 |
From grand score to action level
The modified Group A and Group B scores are combined in the final table to give the grand score, which maps to one of four action levels:
| Grand score | Action level | Interpretation |
|---|---|---|
| 1 - 2 | Level 1 | Acceptable if the posture is not maintained or repeated for long periods |
| 3 - 4 | Level 2 | Further investigation is needed; changes may be required |
| 5 - 6 | Level 3 | Investigation and changes are needed soon |
| 7 | Level 4 | Investigation and changes are required immediately |
A score of 1 to 2 does not mean "no risk". It means the posture is acceptable only if it is not prolonged or highly repetitive, so review it if the task runs long or the worker reports discomfort. RULA is a screening tool that supports, but does not replace, a full assessment by a competent person.
Frequently Asked Questions
What is RULA used for?
RULA (Rapid Upper Limb Assessment) is a postural screening method that estimates the musculoskeletal risk to a worker's upper limbs. You score the posture of the arm, wrist, neck, trunk and legs, add muscle use and load, and the worksheet produces a grand score from 1 to 7 with a matching action level. It is used to screen workstations, compare before and after an intervention, and prioritise which jobs need a fuller assessment.
What does the RULA score mean?
The grand score maps to four action levels. A score of 1 to 2 is acceptable if the posture is not prolonged or highly repetitive. 3 to 4 means investigate further and changes may be needed. 5 to 6 means investigate and change soon. 7 or above means investigate and change immediately.
What is the difference between RULA and REBA?
RULA focuses on the upper limbs and is well suited to seated, computer-based and assembly work. REBA (Rapid Entire Body Assessment) extends the assessment to the whole body with additional coupling and load considerations, so it suits tasks with significant whole-body postures such as heavy lifting, bending or reaching overhead.
What are the limitations of RULA?
RULA captures a single posture at one moment, so it may not represent a full task cycle. It needs a trained observer to estimate joint angles, does not assess contact stress or environmental factors such as vibration or cold, and focuses on the upper limbs. It is a screening tool that supports, but does not replace, a full assessment by a competent person.
Is this RULA calculator free?
Yes. It runs in your browser with no sign-up, scores the posture live using the standard McAtamney and Corlett tables, and exports a result image. It is a free taste of the full ErgoSphere platform, which can score RULA automatically from markerless motion capture and file the result straight into a project report.
Further Reading
- McAtamney, L., & Corlett, E. N. (1993). RULA: a survey method for the investigation of work-related upper limb disorders. Applied Ergonomics, 24(2), 91-99. doi.org/10.1016/0003-6870(93)90080-S
- Stanton, N. A., Hedge, A., Brookhuis, K., Salas, E., & Hendrick, H. (2005). Handbook of Human Factors and Ergonomics Methods. CRC Press.
- Corlett, E. N. (1995). The evaluation of posture and its effects. In J. R. Wilson & E. N. Corlett (Eds.), Evaluation of Human Work (2nd ed., pp. 662-713). Taylor & Francis.
- ISO 11226:2000. Ergonomics - Evaluation of static working postures. iso.org/standard/19299.html
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