Clinical calculators

87 free clinical calculators for physicians — eGFR, creatinine clearance, QTc, MELD, Wells, CURB-65, HAS-BLED, Child-Pugh, GCS, NIHSS, body surface area, weight-based dosing and more. No sign-up, free.

Risk & scoring

• CHA₂DS₂-VASc score
• HEART score
• MELD-Na score
• Wells score — DVT
• Wells score — PE
• CURB-65
• qSOFA
• Glasgow Coma Scale (GCS)
• Child-Pugh score
• Ranson criteria (non-gallstone)
• NIHSS (stroke scale)
• PERC rule (PE)
• Geneva score (revised)
• HAS-BLED (bleeding risk)
• Centor / McIsaac (pharyngitis)
• Alvarado score (appendicitis)
• BISAP (pancreatitis)
• SOFA score
• NEWS2 (early warning)
• Padua score (VTE risk)
• Glasgow-Blatchford (GI bleed)
• TIMI (UA/NSTEMI)
• sPESI (PE severity)
• Ottawa ankle rule
• Rockall (pre-endoscopy)
• Ottawa knee rule
• BODE index (COPD)
• DAS28-CRP (RA activity)
• ABCD² (stroke after TIA)
• NEXUS C-spine rule
• SIRS criteria
• Glasgow-Imrie (pancreatitis)
• Braden scale (pressure ulcer)

Kidney & drug clearance

• Creatinine clearance (Cockcroft-Gault)
• eGFR (CKD-EPI 2021)
• eGFR (cystatin C, CKD-EPI 2021)
• Fractional excretion of sodium (FENa)
• Fractional excretion of urea (FEUrea)
• Pediatric eGFR (Schwartz)
• Kt/V (dialysis adequacy)
• KDIGO AKI staging
• eGFR (MDRD, race-free)

Dosing & anthropometry

• Ideal body weight (IBW)
• Body surface area (BSA)
• Weight-based dose (mg/kg)
• Body mass index (BMI)
• Adjusted body weight

Formulas & electrolytes

• Anion gap
• Sodium deficit
• Corrected calcium
• Corrected Na for hyperglycemia
• Serum osmolality (calculated)
• Winter formula
• Free water deficit
• Corrected phenytoin (Sheiner-Tozer)
• Osmolar gap
• FIB-4 (liver fibrosis)
• Maddrey discriminant function
• Serum-ascites albumin gradient (SAAG)
• HbA1c → estimated average glucose
• MELD 3.0
• HOMA-IR (insulin resistance)
• Delta ratio (delta-delta)
• Light criteria (pleural fluid)

Cardiovascular

• Mean arterial pressure (MAP)
• Corrected QT (QTc)
• Shock index
• Cardiac output (Fick)

Fluids & emergency

• Parkland formula (burns)
• IV drip rate (gtt/min)
• IV infusion rate (mL/h)
• Alveolar-arterial (A-a) gradient

Obstetrics & pediatrics

• APGAR score
• Gestational age & due date (EDD)
• Maintenance fluids (4-2-1 rule)

Hematology

• Transferrin saturation (TSAT)
• Corrected reticulocyte / RPI
• Mentzer index

Psychiatry

• PHQ-9 (depression)
• GAD-7 (anxiety)
• CAGE (alcohol screen)
• CIWA-Ar (alcohol withdrawal)
• AUDIT-C (alcohol screen)
• COWS (opioid withdrawal)

Unit converters

• Temperature (°C ↔ °F)
• Glucose (mg/dL ↔ mmol/L)
• Creatinine (mg/dL ↔ µmol/L)