Medical calculators
Clinical scores and formulas — each with its primary source.
158 calculators
Cardiology16
- CHA₂DS₂-VAStroke risk in atrial fibrillation (ESC 2024, sex removed)
- HAS-BLEDMajor bleeding risk on anticoagulation
- HEART Score6-week MACE risk in chest pain
- Shock indexHeart rate ÷ systolic blood pressure — bedside marker of hypovolaemic shock
- ÖGARI pre-operative cardiac work-up (Austrian guideline 2026)ECG, echocardiography and cardiac biomarkers before elective non-cardiac surgery by METs, surgical category and symptoms
- SCORE2 (ESC 2021, age 40–69)10-year risk of fatal and non-fatal cardiovascular disease in apparently healthy Europeans aged 40–69
- SCORE2-OP (ESC 2021, age ≥ 70)10-year risk of fatal and non-fatal cardiovascular disease in apparently healthy Europeans aged 70 and over
- CHA₂DS₂-VAScStroke risk in atrial fibrillation (classic score incl. female sex)
- Marburg Heart Score (Marburger Herz-Score)Rules out coronary heart disease as the cause of chest pain in primary care
- H₂FPEF scoreLikelihood of heart failure with preserved ejection fraction in unexplained dyspnoea
- TIMI risk score (UA/NSTEMI)14-day risk of death, MI or urgent revascularisation in unstable angina / NSTEMI
- QTc (Bazett / Fridericia)Heart-rate-corrected QT interval with Bazett or Fridericia
- Mean arterial pressure (MAP)Mean arterial pressure from systolic and diastolic blood pressure
- Revised Cardiac Risk Index (Lee)Risk of major cardiac complications after elective non-cardiac surgery
- Duke Activity Status Index (DASI)Self-reported functional capacity before surgery, with estimated VO₂peak
- Wells score (deep vein thrombosis)Pre-test probability of leg DVT (two-level: likely / unlikely)
Respiratory / Infection21
- Wells score (pulmonary embolism)Clinical probability for PE
- CURB-65Severity and site of care in community-acquired pneumonia
- qSOFABedside alert for poor outcome in suspected infection
- CRB-65Mortality risk and treatment setting in community-acquired pneumonia — no blood test needed
- BODE index (COPD)Multidimensional mortality risk grading in stable COPD
- GOLD ABE assessment (COPD)Initial COPD group (A, B, E) to guide first pharmacological treatment — GOLD 2023+
- DECAF score (COPD exacerbation)In-hospital mortality risk in patients admitted with an acute exacerbation of COPD
- A–a oxygen gradientAlveolar–arterial O₂ difference from a blood gas, in kPa (mmHg input accepted)
- PaO₂/FiO₂ ratio (ARDS severity, Berlin)Oxygenation index with Berlin ARDS severity grading; PaO₂ in kPa or mmHg
- ROX index (high-flow nasal oxygen)Predicts success or failure of high-flow nasal oxygen in hypoxaemic respiratory failure
- Light's criteria (pleural effusion)Classify a pleural effusion as exudate or transudate
- Murray lung injury scoreSeverity of acute lung injury from chest X-ray, oxygenation, PEEP and compliance
- Predicted body weight & protective tidal volumeTidal volume in mL from predicted body weight (ARDSNet formula) for lung-protective ventilation
- ARISCAT scoreRisk of postoperative pulmonary complications
- Revised Geneva score (simplified)Clinical pre-test probability of pulmonary embolism, one point per item
- YEARS algorithmRule out pulmonary embolism with a D-dimer threshold adapted to three clinical items
- Age-adjusted D-dimer cut-offD-dimer threshold for excluding PE in patients over 50 (age × 10 µg/L)
- PERC rulePulmonary Embolism Rule-out Criteria — skip D-dimer when gestalt probability is already low
- sPESI (simplified Pulmonary Embolism Severity Index)30-day mortality risk in confirmed acute pulmonary embolism
- PESI (Pulmonary Embolism Severity Index)30-day mortality risk class (I–V) in confirmed acute pulmonary embolism
- Hestia criteriaEligibility for outpatient treatment of acute pulmonary embolism
Neurology13
- Glasgow Coma ScaleLevel of consciousness
- 4AT (delirium screen)Rapid delirium and cognitive-impairment screen for adults in acute care
- Canadian CT Head RuleNeed for head CT after minor head injury (GCS 13–15) in adults
- Canadian C-Spine RuleNeed for cervical-spine imaging in alert, stable adults after blunt trauma
- NEXUS criteria (cervical spine)Clinical clearance of the cervical spine without imaging after blunt trauma
- NIH Stroke Scale (NIHSS)Standardised severity of the neurological deficit in acute stroke
- Modified Rankin Scale (mRS)Global disability and dependence after stroke
- ABCD² scoreEarly stroke risk after transient ischaemic attack (TIA)
- ICH score30-day mortality risk in spontaneous intracerebral haemorrhage
- Hunt & Hess scaleClinical grade of aneurysmal subarachnoid haemorrhage
- WFNS grade (subarachnoid haemorrhage)GCS-based clinical grade of subarachnoid haemorrhage
- Modified Fisher scaleCT grade of subarachnoid haemorrhage — risk of symptomatic vasospasm
- RACE scalePrehospital screen for large-vessel occlusion in suspected stroke
Renal11
- eGFR (CKD-EPI 2021)Estimated glomerular filtration rate, race-free equation
- Creatinine clearance (Cockcroft-Gault)The CrCl estimate many product labels refer to for dose adjustment
- eGFR (EKFC equation)European Kidney Function Consortium creatinine eGFR, valid from childhood to old age
- KDIGO AKI stagingAcute kidney injury stage from creatinine rise, urine output and dialysis
- Kidney Failure Risk Equation (4-variable)2- or 5-year risk of kidney failure (dialysis / transplant) in CKD G3–G5
- FENa (fractional excretion of sodium)Separate prerenal azotaemia from acute tubular necrosis in oliguric AKI
- FEUrea (fractional excretion of urea)Prerenal vs tubular AKI when the patient has received diuretics
- Creatinine µmol/L → mg/dLConvert serum creatinine from SI (µmol/L) to conventional units (mg/dL)
- Creatinine mg/dL → µmol/LConvert serum creatinine from conventional units (mg/dL) to SI (µmol/L)
- Urea mmol/L → BUN mg/dLConvert SI urea (mmol/L) to US blood urea nitrogen (BUN, mg/dL)
- Urea mg/dL → BUN mg/dLConvert urea in mg/dL (German “Harnstoff”, Turkish “üre”) to blood urea nitrogen (BUN)
Gastroenterology / hepatology20
- Appendicitis Inflammatory Response (AIR) scoreProbability of acute appendicitis from clinical signs, WBC, neutrophils and CRP
- Alvarado score (MANTRELS)Clinical score for suspected acute appendicitis
- VITRO score (VWF/platelet ratio)Non-invasive estimate of clinically significant portal hypertension in compensated advanced chronic liver disease
- Baveno VII–VITRO algorithm for CSPHRule in or rule out clinically significant portal hypertension from liver stiffness, platelets and VITRO
- Glasgow-Blatchford scorePre-endoscopy risk in upper GI bleeding — who can be managed as an outpatient
- Rockall score (pre-endoscopy)Clinical Rockall score at presentation in upper GI bleeding, before endoscopy
- Rockall score (complete, post-endoscopy)Mortality and rebleeding risk after endoscopy in upper GI bleeding
- Child-Pugh scoreSeverity of chronic liver disease / cirrhosis (class A, B, C)
- MELD score (UNOS / OPTN)Original MELD — 3-month mortality in end-stage liver disease
- MELD-Na (OPTN 2016)MELD with serum sodium — US liver allocation 2016–2023
- reMELD-Na (Eurotransplant labMELD)Eurotransplant's refitted MELD-Na, used for liver allocation since 25 March 2025
- FIB-4 indexRule out advanced liver fibrosis with routine blood tests (MASLD, viral hepatitis)
- NAFLD fibrosis score (NFS)Advanced fibrosis in fatty liver disease (MASLD/NAFLD)
- BISAP scoreEarly in-hospital mortality risk in acute pancreatitis (first 24 h)
- Maddrey discriminant functionSeverity of alcohol-associated hepatitis — who may benefit from corticosteroids
- Lille modelResponse to corticosteroids on day 7 in severe alcohol-associated hepatitis
- Ranson criteria (acute pancreatitis)Severity of non-gallstone acute pancreatitis at admission and 48 h
- Glasgow–Imrie score (acute pancreatitis)Severity prediction in acute pancreatitis within 48 hours (any aetiology)
- Boey score (perforated peptic ulcer)Operative mortality risk in perforated peptic ulcer
- Mannheim Peritonitis Index (MPI)Mortality risk in secondary peritonitis, scored at laparotomy
Metabolic18
- Body mass indexWeight-for-height index
- Anion gapClassification of metabolic acidosis
- Corrected calciumTotal calcium corrected for albumin
- LDL cholesterol (Friedewald)Calculated LDL-C in mmol/L, read against ESC/EAS 2019 targets
- Corrected sodium in hyperglycaemiaSodium corrected for the dilutional effect of high glucose (Hillier factor 2.4)
- Estimated average glucose from HbA1cTranslate HbA1c (IFCC mmol/mol or %) into average glucose in mmol/L (ADAG)
- Winters’ formula (expected pCO₂)Expected respiratory compensation in metabolic acidosis, in mmHg
- Winters’ formula in kPaExpected pCO₂ in metabolic acidosis for blood gas analysers reporting kPa
- Delta ratio (Δ anion gap / Δ HCO₃⁻)Look for a second metabolic disorder alongside a high anion gap acidosis
- Henderson–Hasselbalch pH checkCalculate pH from HCO₃⁻ and pCO₂ to check a blood gas for internal consistency
- Glucose mmol/L → mg/dLConvert blood or plasma glucose from mmol/L to mg/dL
- Glucose mg/dL → mmol/LConvert blood or plasma glucose from mg/dL to mmol/L
- HbA1c % → mmol/molConvert HbA1c from NGSP/DCCT percent to IFCC mmol/mol
- HbA1c mmol/mol → %Convert HbA1c from IFCC mmol/mol to NGSP/DCCT percent
- Cholesterol mmol/L → mg/dLConvert total, LDL or HDL cholesterol from mmol/L to mg/dL
- Triglycerides mmol/L → mg/dLConvert serum triglycerides from mmol/L to mg/dL
- Calcium mmol/L → mg/dLConvert total or ionised calcium from mmol/L to mg/dL
- 25-OH vitamin D nmol/L → ng/mLConvert 25-hydroxyvitamin D from nmol/L to ng/mL
Psychiatry7
- PHQ-9 (Patient Health Questionnaire-9)Depression severity over the last 2 weeks
- PHQ-2Two-item depression screen (mood and anhedonia)
- GAD-7 (Generalized Anxiety Disorder-7)Anxiety severity over the last 2 weeks
- GAD-2Two-item anxiety screen (core items of the GAD-7)
- AUDIT (Alcohol Use Disorders Identification Test)Hazardous drinking, harmful use and possible dependence (past year)
- AUDIT-CThree-item alcohol consumption screen with sex-specific cut-offs
- CIWA-Ar (alcohol withdrawal)Severity of alcohol withdrawal, for symptom-triggered treatment
Obstetrics / gynaecology3
General49
- Centor scoreProbability of group A streptococcal pharyngitis in adolescents and adults (≥ 15 years)
- McIsaac score (modified Centor)Age-adjusted probability of group A streptococcal pharyngitis from 3 years of age
- FeverPAIN scoreLikelihood of streptococcal (group A/C/G) sore throat in primary care, from 3 years of age
- NEWS2National Early Warning Score 2 — detecting clinical deterioration in adults (SpO₂ scale 1)
- SOFA scoreSequential (Sepsis-related) Organ Failure Assessment — organ dysfunction for the Sepsis-3 definition
- SIRS criteriaSystemic inflammatory response syndrome (ACCP/SCCM 1992)
- Ottawa ankle rulesNeed for ankle or foot radiographs after acute ankle injury in adults
- ÖGARI pre-operative laboratory tests (Austrian guideline 2026)Which pre-operative blood tests the Austrian ÖGARI guideline recommends by ASA class and surgical category
- SAPS 3 admission scoreICU severity of illness from data within 1 hour of ICU admission
- SAPS 3 predicted hospital mortalityConvert a SAPS 3 admission score into predicted hospital mortality (general or Central/Western Europe equation)
- TISS-28 (Therapeutic Intervention Scoring System)Daily ICU nursing workload from 28 therapeutic activities
- ECOG performance statusFunctional status grade (0–5) in patients with cancer
- Karnofsky performance statusFunctional status (0–100 %) with ECOG equivalent
- International Prognostic Index (IPI)Prognosis in aggressive non-Hodgkin lymphoma (DLBCL)
- Revised IPI (R-IPI)Prognosis in DLBCL treated with R-CHOP
- FLIPI (Follicular Lymphoma International Prognostic Index)Risk group at diagnosis of follicular lymphoma
- 4Ts score (heparin-induced thrombocytopenia)Pre-test probability of HIT
- ISTH overt DIC scoreLaboratory score for overt disseminated intravascular coagulation
- PLASMIC scoreLikelihood of severe ADAMTS13 deficiency (TTP) in thrombotic microangiopathy
- HScore (reactive haemophagocytic syndrome)Probability of secondary HLH in adults
- MASCC risk index (febrile neutropenia)Identifies low-risk febrile neutropenia suitable for outpatient care
- CISNE score (Clinical Index of Stable Febrile Neutropenia)Risk of serious complications in apparently stable febrile neutropenia (solid tumours)
- DAS28-ESRDisease Activity Score in 28 joints with ESR — rheumatoid arthritis
- DAS28-CRPDisease Activity Score in 28 joints with CRP — rheumatoid arthritis
- CDAI (Clinical Disease Activity Index)Laboratory-free disease activity in rheumatoid arthritis
- SDAI (Simplified Disease Activity Index)Disease activity in rheumatoid arthritis including CRP
- ASDAS-CRPAxial Spondyloarthritis Disease Activity Score (CRP version)
- 2010 ACR/EULAR rheumatoid arthritis classification criteriaClassifies newly presenting synovitis as definite RA (≥ 6/10 points)
- 2015 ACR/EULAR gout classification criteriaClassifies gout from clinical, laboratory and imaging findings (≥ 8 points)
- Absolute neutrophil count (ANC)Neutrophils per litre from the white cell count and differential, with neutropenia grade
- Reticulocyte production index (RPI)Correct the reticulocyte percentage for anaemia and early release to judge marrow response
- Bilirubin µmol/L → mg/dLConvert total or direct bilirubin from µmol/L to mg/dL
- Corticosteroid conversion (prednisolone equivalent)Convert a systemic glucocorticoid dose to its prednisolone-equivalent dose
- PECARN head injury rule (< 2 years)Need for CT after minor head trauma in children under 2 (GCS 14–15)
- PECARN head injury rule (≥ 2 years)Need for CT after minor head trauma in children aged 2–17 (GCS 14–15)
- Paediatric Glasgow Coma ScaleLevel of consciousness in preverbal children (≤ 2 years)
- APACHE IIICU severity of illness from the worst values in the first 24 hours
- Richmond Agitation-Sedation Scale (RASS)Depth of sedation and agitation in ICU patients
- Apfel score (PONV)Risk of postoperative nausea and vomiting in adults
- Modified Aldrete scoreReadiness for discharge from the post-anaesthesia care unit (PACU)
- Parkland formula (burns)Initial 24-hour crystalloid estimate in major burns
- Holliday–Segar maintenance fluidsDaily maintenance fluid requirement by body weight (100/50/20 rule)
- Revised Trauma Score (RTS)Physiological severity of injury (weighted RTS, 0–7.84)
- Revised Baux score (burns)Burn mortality index combining age, burn size and inhalation injury
- Surgical Apgar ScoreIntraoperative 10-point score for 30-day major complications or death
- Padua Prediction ScoreVTE risk in hospitalised medical patients — who needs thromboprophylaxis
- Khorana scoreRisk of chemotherapy-associated VTE in ambulatory cancer patients
- Vienna CATS score (CATS/MICA model)6-month risk of cancer-associated VTE from tumour site and D-dimer
- IMPROVE bleeding risk scoreIn-hospital bleeding risk in acutely ill medical patients before thromboprophylaxis