Emergency Medicine Calculators
40 calculators & risk scores
Browse 40 Emergency Medicine clinical calculators and risk scores used in everyday UK practice. Every tool runs entirely in your browser — enter the values and get instant scoring, colour-coded interpretation bands and a link to the underlying guideline or publication. ClinCalc Pro is free, needs no sign-up, and is built for working clinicians.
These emergency medicine tools span Neurological, Venous Thromboembolism, Infection, Early Warning, Sepsis, Stroke / TIA and more.
- Glasgow Coma ScaleAssesses level of consciousness via eye, verbal, and motor responses
- Wells Criteria for PEEstimates pre-test probability of pulmonary embolism
- Wells Criteria for DVTEstimates pre-test probability of deep vein thrombosis
- PERC Rule for PERules out PE without further testing in low pretest probability patients
- Revised Geneva Score for PEObjective clinical score for pre-test probability of pulmonary embolism
- CURB-65 Score for PneumoniaEstimates 30-day mortality risk and guides admission decisions in community-acquired pneumonia
- NEWS2 ScoreNational Early Warning Score 2 — identifies patients at risk of deterioration
- qSOFA Score for SepsisQuick bedside screen for sepsis-related organ dysfunction outside ICU
- SOFA ScoreQuantifies organ dysfunction in ICU/HDU; sequential increase ≥2 defines sepsis
- ABCD² Score for TIAPredicts 2-day stroke risk following a transient ischaemic attack
- Alvarado Score for AppendicitisEstimates likelihood of acute appendicitis in patients with right iliac fossa pain
- Ottawa Ankle RulesDetermines need for ankle and foot X-ray following acute injury
- Ottawa Knee RuleDetermines need for knee X-ray following acute knee injury
- NEXUS C-Spine CriteriaIdentifies patients who can have cervical spine cleared without radiography
- Fisher Grade (SAH)Grades amount of subarachnoid blood on CT to predict vasospasm risk
- Revised Trauma ScorePredicts survival probability in trauma using GCS, systolic BP, and respiratory rate
- Centor Score for Strep PharyngitisEstimates probability of Group A Streptococcal pharyngitis to guide testing and antibiotic use
- Modified Early Warning ScoreBedside early warning score to identify patients at risk of clinical deterioration
- Pre-Endoscopy Rockall ScoreEstimates risk of mortality in upper GI bleeding before endoscopy
- Rumack-Matthew NomogramDetermines need for N-acetylcysteine (NAC) treatment following paracetamol (acetaminophen) overdose based on serum level and time post-ingestion
- Naranjo Adverse Drug Reaction ScaleStandardised questionnaire to assess the probability that an adverse drug reaction (ADR) is caused by a specific drug
- Osmol GapCalculates the difference between measured and calculated serum osmolality to detect unmeasured osmoles (e.g. toxic alcohols, mannitol)
- Estimated Blood Alcohol ConcentrationEstimates blood alcohol concentration (BAC) using the Widmark formula based on drinks consumed, body weight, sex, and drinking duration
- Done Nomogram (Salicylate Toxicity)Estimates severity of acute salicylate (aspirin) poisoning based on serum salicylate level and hours post-ingestion
- Rapid Emergency Medicine Score (REMS)Predicts in-hospital mortality in non-traumatic adult ED patients using 6 physiological variables: age, MAP, HR, RR, SpO₂, and GCS
- Canadian C-Spine RuleDetermines need for cervical spine imaging after blunt trauma. Validated in alert, stable patients. More specific than NEXUS.
- NEXUS Low-Risk Criteria (C-Spine)Five low-risk criteria to rule out cervical spine injury without imaging in blunt trauma patients. All criteria must be met to clear.
- Ottawa Ankle and Knee RulesClinical decision rules to guide radiography in ankle and knee injuries. Highly sensitive for fracture; reduces unnecessary imaging.
- FOUR Score (Full Outline of UnResponsiveness)Coma scale assessing eye response, motor response, brainstem reflexes, and respiration. Outperforms GCS for intubated patients.
- Pulmonary Embolism Severity Index (PESI)Predicts 30-day mortality in acute pulmonary embolism. Guides decision between inpatient vs outpatient management.
- SIRS Criteria and Sepsis DefinitionIdentifies systemic inflammatory response syndrome (SIRS) and sepsis. Two or more SIRS criteria with suspected infection = sepsis (Sepsis-2 definition).
- STONE Score (Ureteral Stone Prediction)Predicts likelihood of ureteral stone on CT KUB in patients presenting with suspected renal colic. Helps avoid unnecessary CT in low-risk patients.
- Primary Survey Assessment (ABCDE / ATLS)Systematic ABCDE primary survey documentation for trauma and critically ill patients per ATLS/ALS. Identifies life-threatening conditions requiring immediate intervention.
- Manchester Triage System (MTS) CategoryAssigns Manchester Triage System priority category based on presenting discriminators. Determines maximum wait time for clinical assessment.
- Revised Trauma Score (RTS)Physiological trauma severity score using GCS, systolic BP, and respiratory rate. Used for triage, survival prediction, and outcome benchmarking.
- Thrombolysis vs PCI Decision (STEMI)Guides reperfusion strategy in STEMI: primary PCI vs thrombolysis based on time from symptoms, accessibility, and contraindications per ESC/NICE guidelines.
- CT Head Rules (NICE/Canadian)Combines NICE CG176 and Canadian CT Head Rule criteria for immediate CT head in adults with head injury. Reduces unnecessary CT while identifying neurosurgically significant injuries.
- Numeric Rating Scale (NRS) Pain Assessment and ManagementNumerical Rating Scale (0-10) for pain assessment. Guides analgesic ladder escalation in ED and inpatient settings per WHO/BPS guidelines.
- MEDS — Mortality in Emergency Department SepsisPredicts 28-day mortality in adult ED sepsis (Shapiro 2003). Sums 9 weighted criteria.
- NISS — New Injury Severity ScoreModification of the Injury Severity Score (Osler 1997). Sum of squares of the AIS scores of the three most severe injuries regardless of body region. Range 0–75 (any AIS 6 → automatic 75). Better predictor of mortality than ISS in penetrating and blunt trauma.