Emergency Medicine medical calculators
Trauma, triage, and acute risk scores used in the ED.
Emergency medicine calculators help standardize triage, risk stratification, and rule-out pathways when time is limited. Tools here include Wells and PERC for pulmonary embolism, HEART and TIMI for chest pain, qSOFA for sepsis screening, Ottawa ankle rules, and pediatric weight estimation for resuscitation. Each page documents the score components, evidence limitations, and when a negative result still requires clinical follow-up.
29 calculators
A–a Oxygen Gradient
A–a GradientCalculate the alveolar–arterial oxygen gradient from ABG values and compare with age-expected normals.
Absolute Neutrophil Count (ANC)
ANCCompute absolute neutrophil count from WBC and neutrophil/band percentages or fractions.
Allowable Blood Loss & EBV
ABL / EBVEstimate blood volume by age group and calculate allowable blood loss before a target hematocrit.
Alvarado Score (Appendicitis)
AlvaradoScore clinical likelihood of acute appendicitis using the Alvarado (MANTRELS) criteria.
Anion Gap Calculator
Anion GapCalculate serum anion gap with optional albumin correction for acid-base workups.
Bicarbonate Deficit
HCO₃ DeficitEstimate bicarbonate deficit from weight, current HCO₃, and target.
Burns TBSA & Parkland Formula
Burns / ParklandEstimate percent TBSA with Rule of Nines and calculate Parkland crystalloid resuscitation volumes.
Centor / McIsaac Strep Score
CentorEstimate group A strep pharyngitis probability with the modified Centor (McIsaac) score.
Corrected QT (QTc)
QTcCorrect the QT interval for heart rate using Bazett or Fridericia formulas.
Corrected Sodium (Hyperglycemia)
Corrected NaCorrect measured sodium for hyperglycemia using Katz (1.6) or Hillier (2.4) factors.
CURB-65 Pneumonia Severity
CURB-65Stratify community-acquired pneumonia severity and site-of-care decisions using CURB-65.
Free Water Deficit
Free Water DeficitEstimate free water deficit in hypernatremia for replacement planning.
Glasgow Coma Scale (GCS)
GCSScore eye, verbal, and motor responses for rapid neurologic assessment in trauma and critical care.
Glasgow-Blatchford Score (UGIB)
GBSRisk-stratify upper GI bleeding for need for intervention and safe outpatient management.
HEART Score for Chest Pain
HEARTRisk-stratify ED chest pain for short-term major adverse cardiac events using HEART.
Infusion Rate (mL/h)
Infusion RateConvert mcg/kg/min or mg/kg/h infusions and bag concentration into mL/h pump rates.
Mean Arterial Pressure (MAP)
MAPCompute mean arterial pressure from systolic and diastolic blood pressure.
mg/kg Dose Calculator
mg/kgConvert a mg/kg dose and patient weight into a total milligram dose and optional volume.
NEXUS C-Spine Rule
NEXUSApply NEXUS low-risk criteria to help decide whether cervical spine imaging is needed after trauma.
Ottawa Ankle Rules
Ottawa AnkleDecide whether ankle or foot radiographs are indicated after acute blunt injury using Ottawa rules.
Pediatric ETT Size
Peds ETTEstimate pediatric endotracheal tube internal diameter and approximate oral insertion depth from age.
Pediatric Weight Estimation
Peds WeightEstimate pediatric weight from age using APLS, Luscombe & Owens, and Best Guess formulas — plus infant and neonate modes.
PERC Rule for PE
PERCApply the PERC rule to help rule out pulmonary embolism in low-risk patients.
qSOFA Score
qSOFAQuick bedside screen for patients with suspected infection at higher risk of poor outcomes.
Serum Osmolality & Osmolar Gap
OsmolalityCalculate serum osmolality and optional osmolar gap for toxic alcohol and hyperosmolar workups.
Sodium Deficit
Na DeficitEstimate sodium deficit for hyponatremia replacement planning.
TIMI Risk Score (UA/NSTEMI)
TIMIEstimate risk in unstable angina / NSTEMI using the TIMI risk score.
Wells Score for DVT
Wells DVTEstimate pretest probability of lower-extremity deep vein thrombosis with the Wells DVT criteria.
Wells Score for PE
Wells PEEstimate pretest probability of pulmonary embolism with the Wells PE criteria.