Westley Croup Score Calculator
Westley Croup Score Calculator
Five observations, 0 to 17, with two late signs carrying ten of the seventeen points. It was derived as the outcome measure of a 20-child drug trial in 1978, not as a triage instrument, and the severity bands in circulation disagree by two points.
Westley croup score
5 items, 0 to 17Stridor at rest (2); mild retractions (1); decreased air entry (1); no cyanosis (0); alert (0)
Scoring
Minimum 0 · maximum 17 · mild 0–2 · moderate 3–5 · severe 6–11 · impending respiratory failure 12–17
- the score is not linear
- cyanosis and altered consciousness carry 10 of the 17 points between them, so the distance from 5 to 10 is one observation and the distance from 0 to 5 is every other item at once. A total is not an index of effort
- what it was derived for
- Westley, Cotton and Brooks published it in 1978 as the outcome measure of a double-blind trial of nebulised racemic epinephrine by IPPB in 20 children. It was derived in that setting to detect change within a child over hours, which is what a trial endpoint has to do, and it has no derivation cohort attaching a band to an outcome
- two sources, two moderate bands
- RCEM Learning and published croup guidelines give moderate as 3–5 and severe as 6–11; the MSD Manual gives moderate as 3–7 and severe as 8–11. A child scoring 6 or 7 is in a different category depending on which chart is on the wall
- cyanosis or saturation
- the original item is visible cyanosis, graded on agitation or at rest. Several reproductions substitute an oxygen saturation under 92 per cent at the same 4 and 5 weights. Both are in circulation and they are different observations
- reliability was never established
- a critically appraised topic reviewing the paediatric respiratory severity scores reports Justicia-Grande and colleagues’ 2017 systematic review as finding reliability, validity and responsiveness not established for 40 such scales, a croup scoring instrument among them, and concludes that “a recommendation cannot be made to select one score to determine degree of respiratory distress”
Worked example
Stridor at rest (2); mild retractions (1); decreased air entry (1); no cyanosis (0); alert (0)
2 + 1 + 1 + 0 + 0 = 4 points, in the 3–5 moderate band as this page implements it
On the MSD Manual's banding of the same score, 4 is also moderate — but 6 and 7 are moderate there and severe here, so the two charts only agree below 6
Change nothing except the child's alertness, to disoriented, and the total jumps from 4 to 9: one observation crosses two bands, because that item alone is worth 5
Change nothing except colour, to cyanosis at rest, and the total goes to 9 as well. Those two items carry 10 of the 17 points between them
Add every other item at its maximum instead — stridor 2, retractions 3, air entry 2 — and the total is 7. The three items an examiner spends most time grading cannot reach the top band on their own
The five observations
| Observation | 0 | 1 | 2 | 3 or more |
|---|---|---|---|---|
| Inspiratory stridor | None | With agitation | At rest | — |
| Chest wall retractions | None | Mild | Moderate | Severe (3) |
| Air entry | Normal | Decreased | Markedly decreased | — |
| Cyanosis | None | — | — | With agitation (4), at rest (5) |
| Level of consciousness | Normal, including sleep | — | — | Disoriented (5) |
The severity bands, and where the sources disagree
| Total | This page (RCEM Learning; croup guidelines) | MSD Manual |
|---|---|---|
| 0 to 2 | Mild | Mild |
| 3 to 5 | Moderate | Moderate |
| 6 to 7 | Severe | Moderate |
| 8 to 11 | Severe | Severe |
| 12 to 17 | Impending respiratory failure | Impending respiratory failure |
A trial endpoint that became a triage tool
The Westley score is five observations: stridor, chest wall retractions, air entry, cyanosis and level of consciousness. Three of them are graded in small steps worth 1, 2 or 3 points. The other two jump. Cyanosis scores 4 on agitation and 5 at rest; altered consciousness is binary and scores 5. So ten of the seventeen available points sit behind two late observations, and a child whose stridor, retractions and air entry are all as bad as the score can record them still totals only 7. Reading the total as a smooth measure of how hard a child is working is the commonest mistake made with it.
It helps to know where the score came from. Westley, Cotton and Brooks published it in 1978 as the outcome measure of a double-blind trial of nebulised racemic epinephrine delivered by intermittent positive-pressure breathing, in twenty children. A trial endpoint has to be sensitive to change within one child over a couple of hours, and this one is. What it never had was a derivation cohort linking a band to an outcome, and the severity bands now printed on wall charts everywhere were added afterwards by other people. They do not agree: RCEM Learning and published croup guidelines give 3 to 5 as moderate and 6 to 11 as severe, while the MSD Manual gives 3 to 7 as moderate and 8 to 11 as severe. A child scoring 6 is severe on one chart and moderate on the other, and that gap sits in the busiest part of the range. The item definitions have drifted too: several reproductions replace visible cyanosis with an oxygen saturation under 92 per cent, keeping the 4 and 5 weights.
The wider evidence is worth stating plainly rather than leaving in a footnote. A critically appraised topic reviewing the paediatric respiratory severity scores reports Justicia-Grande and colleagues’ 2017 systematic review as finding reliability, validity and responsiveness not established for forty such scales, and concludes in its own words that “a recommendation cannot be made to select one score to determine degree of respiratory distress”. That is not a reason to stop counting; it is a reason to hand over the five items rather than the total, and to score the child once they have settled, since examining a frightened toddler inflates stridor and retractions together. A score is not a diagnosis, and a published figure describes the cohort it came from rather than the child in front of you. A single value is a snapshot of one examination: a child whose illness is evolving can score differently an hour later, so a reassuring score does not exclude deterioration, and the trend across serial assessments by the same examiner carries more than any one reading. The derivation setting is children with croup aged roughly six years and under; it was not derived in, and says nothing about, bacterial tracheitis, epiglottitis or an inhaled foreign body. Published item wordings and severity bands differ between sources and between units, so the reader’s own unit’s chart and protocol take precedence over any banding printed here.
Frequently asked questions
What is the maximum Westley croup score?
17. Stridor contributes up to 2, retractions up to 3, air entry up to 2, cyanosis up to 5 and level of consciousness up to 5. The three items an examiner grades most carefully can only reach 7 between them.
What Westley score counts as severe croup?
It depends which source is on the wall, and the disagreement is two points wide. RCEM Learning and published croup guidelines give severe as 6 to 11; the MSD Manual gives severe as 8 to 11 and calls 6 and 7 moderate. Westley’s own 1978 paper published no severity bands at all.
Does a sleeping child score for altered consciousness?
No. The published item is “normal, including sleep” for 0 points and “disoriented” for 5. A child with croup who is asleep is not obtunded, and scoring normal sleep as altered consciousness adds five points to a night-time total for nothing.
Is the Westley score validated?
As a trial endpoint it has been used for decades, including in the Cochrane review of nebulised epinephrine. As a severity classification it is weaker: a review of forty paediatric respiratory severity scales found reliability, validity and responsiveness not established, and the appraisal that reports it concludes that no one score can be recommended for grading respiratory distress.
Should I use cyanosis or oxygen saturation for the fourth item?
The original 1978 item is visible cyanosis, graded none, with agitation, or at rest. Several widely used reproductions substitute an oxygen saturation under 92 per cent in room air at the same weights. Both are in circulation, they are different observations, and totals built from the two are not comparable — so record which version was used.
Related calculators
References
- Westley CR, Cotton EK, Brooks JG. Nebulized racemic epinephrine by IPPB for the treatment of croup: a double-blind study. Am J Dis Child. 1978;132(5):484–487. The citation and the trial’s size were read on Guideline Central’s score page and in the Cochrane review of nebulized epinephrine for croup; the paper itself is not open access and was not opened.
- Royal College of Emergency Medicine Learning. Westley Croup Score, in Acute stridor. rcemlearning.co.uk (accessed 10 October 2026).
- MSD Manual Professional Edition. Westley croup severity score (medical calculator, children 6 years and under). Rahway, NJ: Merck & Co (accessed 10 October 2026).
- University of Missouri School of Medicine, Department of Emergency Medicine. Croup Clinical Practice Guideline, version 5 (accessed 10 October 2026) — cites Westley 1978 and Yang W-C et al. Pediatr Pulmonol. 2017;52(10):1329–1334.
- Children’s Mercy Kansas City, Evidence Based Practice. Respiratory scores (critically appraised topic) — reviews the paediatric asthma, bronchiolitis and respiratory distress scores and reports Justicia-Grande AJ et al. (2017) as finding reliability, validity and responsiveness not established for 40 such scales (accessed 10 October 2026).
Not medical advice. For healthcare professionals and education. Reference intervals vary by laboratory and assay — always use your own laboratory's. Never base a dose or a treatment decision on this page alone. Full disclaimer at calcengines.com/disclaimer/