This calculator is for general information and education. It is not medical advice and does not replace the judgment of a doctor, nurse or pharmacist who knows the full clinical picture.
On a hospital ward, patients often show warning signs hours before a cardiac arrest or an emergency transfer to intensive care. Early warning scores turn routine vital signs into a single number, so nurses know when to call a doctor or the rapid response team. The Modified Early Warning Score (MEWS), validated by Subbe and colleagues in 2001, is one of the most widely used.
The score
| Parameter | 3 | 2 | 1 | 0 | 1 | 2 | 3 |
|---|---|---|---|---|---|---|---|
| Systolic BP (mmHg) | 70 or less | 71 to 80 | 81 to 100 | 101 to 199 | 200 or more | ||
| Heart rate (bpm) | 40 or less | 41 to 50 | 51 to 100 | 101 to 110 | 111 to 129 | 130 or more | |
| Respiratory rate (/min) | under 9 | 9 to 14 | 15 to 20 | 21 to 29 | 30 or more | ||
| Temperature (°C) | under 35 | 35 to 38.4 | 38.5 or more | ||||
| AVPU | Alert | Voice | Pain | Unresponsive |
The calculator converts °F to °C.
Example
A patient with a systolic pressure of 105, a heart rate of 105, a respiratory rate of 18, a temperature of 100 °F (37.8 °C) who is alert scores 0 + 1 + 1 + 0 + 0 = 2: low risk, routine observations.
Interpretation
Hospitals set their own escalation rules, but a common scheme is:
- 0 to 2: low risk, routine monitoring.
- 3 to 4: increased risk, more frequent observations and review by a doctor.
- 5 or more: high risk. In Subbe’s study, a score of 5 or more was linked to a higher risk of death and ICU admission. Urgent medical review is expected.
A single parameter scoring 3 usually also triggers a review, whatever the total.
MEWS or NEWS2?
In the United Kingdom, the NEWS2 score has replaced MEWS in most hospitals. It adds oxygen saturation and supplemental oxygen and has stronger validation. Many US hospitals still use MEWS or a local version of it.
Limits
- The score depends on accurate, complete observations; a missing respiratory rate is a common error.
- Some patients have abnormal baselines (chronic tachycardia, beta-blockers, COPD).
- A low score never overrides a nurse’s or doctor’s concern.