Calculators

Clinical calculators

Bedside calculators for licensed practitioners. Each one prints the equation it implements and the paper it comes from, so you can check the arithmetic rather than take it on faith.

Calculators

Nephrology

eGFR calculator (CKD-EPI 2021)

Estimated glomerular filtration rate from serum creatinine, age and sex.

Inker LA et al., New England Journal of Medicine, 2021
Pharmacology

Creatinine clearance calculator (Cockcroft–Gault)

Estimated creatinine clearance for renal drug dosing.

Cockcroft DW, Gault MH, Nephron, 1976
Paediatrics

Paediatric maintenance fluid calculator

Daily and hourly maintenance fluid requirement by weight.

Holliday MA, Segar WE, Pediatrics, 1957
General

BMI and body surface area calculator

Body mass index with Asian cut-offs, plus BSA by Mosteller and Du Bois.

WHO Expert Consultation, The Lancet, 2004; Mosteller RD, NEJM, 1987; Du Bois D & Du Bois EF, 1916
Acid–base

Anion gap calculator with albumin correction

Anion gap, albumin-corrected gap, and delta ratio in one step.

Figge J et al., Critical Care Medicine, 1998
Biochemistry

Corrected calcium calculator

Adjust total serum calcium for the patient’s albumin.

Payne RB et al., British Medical Journal, 1973
Emergency

Wells score calculator for DVT

Pre-test probability of DVT from the nine-plus-one Wells criteria.

Wells PS et al., The Lancet, 1997; revised 2003
Cardiology

CHA₂DS₂-VASc calculator

Stroke risk stratification in non-valvular atrial fibrillation.

Lip GYH et al., Chest, 2010
Paediatrics

Paediatric weight-based dose calculator

Weight-based dose, adult ceiling cap, and the volume to draw up.

Standard weight-based dosing arithmetic