Revised Trauma Score (RTS) Calculator
Enter the patient's Glasgow Coma Scale score, systolic blood pressure, and respiratory rate to get the weighted Revised Trauma Score (RTS), the simple triage RTS, and an estimated survival probability based on the Champion 1989 logistic model. The calculator shows coded values for each parameter, step-by-step arithmetic, and a clinical interpretation with triage guidance.
What is the Revised Trauma Score?
The Revised Trauma Score (RTS) is a physiological triage and outcome-prediction tool developed by Champion, Sacco, and colleagues and published in the Journal of Trauma in 1989. It replaced the earlier Trauma Score by combining three clinical parameters that can be measured rapidly at the scene or on arrival: the Glasgow Coma Scale (GCS), systolic blood pressure (SBP), and respiratory rate (RR). Because it relies only on observable physiology rather than anatomy, it is well suited to prehospital triage, emergency department intake, and trauma registry benchmarking. A higher RTS indicates a better physiological state and a higher probability of survival.
Weighted RTS vs triage RTS
Two forms of the score exist. The triage RTS is the simple sum of three coded values, one for each parameter, each ranging from 0 to 4, giving a total of 0 to 12. This version is quick to calculate in the field without a calculator and is used in START and similar mass-casualty triage protocols. The weighted RTS uses different regression coefficients for each parameter: 0.9368 for GCS coded value, 0.7326 for SBP coded value, and 0.2908 for RR coded value, giving a range of 0 to 7.8408. The weights reflect the relative prognostic contribution of each variable, with neurological status (GCS) carrying the greatest weight. The weighted form is used in the Trauma and Injury Severity Score (TRISS) methodology and for comparing outcomes across trauma centers.
How the coding table works
Each of the three raw measurements is translated into a coded value from 0 to 4 before the formula is applied. For GCS: 13-15 maps to 4, 9-12 to 3, 6-8 to 2, 4-5 to 1, and 3 (the minimum possible GCS) to 0. For systolic blood pressure: above 89 mmHg maps to 4, 76-89 to 3, 50-75 to 2, 1-49 to 1, and 0 (pulseless) to 0. For respiratory rate: 10-29 breaths per minute maps to 4, above 29 to 3, 6-9 to 2, 1-5 to 1, and 0 (apneic) to 0. Note that both too-low and too-high respiratory rates receive a lower coded value than the normal range, but the maximum coded value of 3 rather than 4 for a rate above 29 reflects the poor prognosis associated with hyperventilation in severe head injury.
Clinical triage thresholds and limitations
An RTS of 4 or below is the widely accepted field criterion for diverting a patient to a trauma center, because the estimated survival probability drops sharply below this threshold. An RTS of 3 or below is associated with a survival probability under 40% and indicates critical physiological compromise requiring the highest-level response. Despite its utility, the RTS has known limitations: it is a static snapshot of physiology at one point in time and can be misleading if measured late after resuscitation, in intubated patients where verbal GCS is unobtainable, or in patients with baseline neurological or respiratory disease. It does not account for the mechanism or anatomical extent of injury, which is why it is most powerful when combined with the Injury Severity Score in the TRISS model.
RTS Coded Values and Survival Probability by Score
| Weighted RTS | Triage RTS | Estimated Survival | Clinical Meaning |
|---|---|---|---|
| 0 | 0 | 2.7% | Likely non-survivable |
| 1 | 1-2 | 7.1% | Critical - immediate intervention |
| 2 | 3-4 | 17.2% | Critical - immediate intervention |
| 3 | 5-6 | 36.1% | Critical - trauma center required |
| 4 | 7-8 | 60.5% | Severe - trauma center recommended |
| 5 | 9-10 | 80.7% | Moderate injury |
| 6 | 11 | 91.9% | Moderate-to-mild injury |
| 7 | 12 | 96.9% | Minor injury |
| 7.84 | 12 | 98.8% | Physiologically normal |
Coded values for each parameter and estimated blunt-trauma survival rates published by Champion et al. (1989). The weighted RTS uses coefficients 0.9368 (GCS), 0.7326 (SBP), and 0.2908 (RR).
Frequently asked questions
What is a normal or good Revised Trauma Score?
The maximum possible weighted RTS is 7.84, which corresponds to a GCS of 13-15, a systolic BP above 89 mmHg, and a respiratory rate of 10-29 breaths per minute. A score of 7.84 is associated with an estimated survival probability of about 98.8%. Most uninjured adults will score 7.84. Any score below 7.84 indicates physiological abnormality in at least one parameter, and a score of 4 or below is considered an indication for trauma center referral.
What RTS score requires a trauma center?
Standard triage guidelines recommend referral to a trauma center for any patient with an RTS of 4 or below. At an RTS of 4, the estimated survival probability is about 60.5%, and it falls rapidly with lower scores. The American College of Surgeons Committee on Trauma has incorporated this threshold into field triage decision schemes. When in doubt, a lower-threshold approach (any score below 6) may be appropriate in systems with readily accessible trauma centers.
What is the difference between triage RTS and weighted RTS?
The triage RTS is the simple arithmetic sum of the three coded values (range 0-12) and is designed for rapid mental calculation in the field or during mass-casualty events. The weighted RTS applies empirically derived coefficients to each coded value - 0.9368 for GCS, 0.7326 for SBP, and 0.2908 for RR - giving a total ranging from 0 to 7.8408. The weighted form is more predictive of survival because it reflects the unequal prognostic contribution of each physiological variable, but it requires a calculator. The weighted RTS is the version used in the TRISS methodology for trauma center benchmarking.
What does a coded value of 3 for respiratory rate mean?
A respiratory rate above 29 breaths per minute is coded as 3, not 4 (the maximum), because tachypnea above this level is associated with a worse prognosis than a normal rate. Rates of 10-29 per minute receive the top coded value of 4. Both extremes of respiratory rate, very slow or very fast, receive progressively lower coded values, reflecting the physiological deterioration associated with abnormal breathing patterns, particularly hyperventilation seen in severe head injury.
Can the RTS be used for pediatric patients?
The RTS was developed and validated primarily in adult trauma populations. For pediatric patients, the Pediatric Trauma Score (PTS) is generally preferred because it incorporates body weight and accounts for the different physiological norms of children. However, the RTS is sometimes applied to older children and adolescents, with the caveat that GCS interpretation and vital sign thresholds differ from adults. Always consult age-specific pediatric triage guidelines when assessing injured children.
Why is GCS weighted more heavily than blood pressure in the formula?
The coefficients in the weighted RTS were derived from logistic regression analysis of a large trauma database. The analysis showed that neurological status, as measured by GCS, was the strongest single predictor of survival in blunt trauma, hence its coefficient of 0.9368. Systolic blood pressure was the second strongest predictor (0.7326), and respiratory rate contributed the least independent predictive information (0.2908). These weights reflect the physiological reality that traumatic brain injury is a major driver of mortality and that GCS captures this more sensitively than the other two parameters.