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Bedside tools

Medical Calculators and Scales

37 calculators and clinical scales across neurology, cardiology, renal, hepatic, respiratory, critical-care, obstetric and mental-health medicine — NIHSS, GCS, CURB-65, HEART, Apgar, PHQ-9 and more. Each one shows the formula it used, what the number means, and — the part most calculators leave out — where it stops being valid.

Nothing is transmitted
Every value is calculated in your browser and sent nowhere.
Sourced
Each calculator cites the paper or guideline it was built from.
Works offline
Once you have opened a calculator, it keeps working without signal.

Nutrition, Calories & Weight GoalNewBMI, BMR and TDEE turned into a daily calorie and macronutrient target, with a MET-based exercise calculator, a food and meal log, and a weight plan that caps itself at a safe rate.Open

Anthropometry

Body Mass Index

Weight-for-height index, reported against both WHO and Asian-Indian cut-offs.

Body Surface Area

Du Bois and Mosteller body surface area, for dosing that is quoted per m².

Ideal & Adjusted Body Weight

Devine ideal body weight, with adjusted body weight for dosing in obesity.

Renal

eGFR (CKD-EPI 2021, creatinine)

Race-free CKD-EPI 2021 estimated GFR, staged to KDIGO G1–G5.

Creatinine Clearance (Cockcroft-Gault)

The estimate most drug labels still specify for renal dose adjustment.

Fractional Excretion of Sodium

Separates pre-renal from intrinsic acute kidney injury.

Electrolytes & acid–base

Albumin-Corrected Calcium

Adjusts total calcium for a low albumin, so hypocalcaemia is not over-called.

Anion Gap

Anion gap with optional albumin correction — the first branch point in a metabolic acidosis.

Sodium Correction for Hyperglycaemia

True sodium behind the dilutional pseudohyponatraemia of a high glucose.

Winter's Formula

Expected pCO₂ in metabolic acidosis — the test for a second, hidden acid–base disorder.

Cardiology

CHA₂DS₂-VASc

Stroke risk in non-valvular atrial fibrillation, and the trigger for anticoagulation.

HAS-BLED

Major bleeding risk on anticoagulation — read as a checklist, not a veto.

HEART Score for Chest Pain

Six-week risk of a major adverse cardiac event in undifferentiated chest pain, scored 0–10.

Corrected QT Interval

QT interval corrected for heart rate, by both Bazett and Fridericia.

Mean Arterial Pressure

Average arterial pressure across the cardiac cycle — the perfusion pressure that matters.

Neurology

NIH Stroke Scale

Fifteen-item bedside quantification of stroke severity, scored 0–42.

Modified Rankin Scale

Global disability after stroke, 0 (no symptoms) to 6 (dead).

ABCD² Score for TIA

Early stroke risk after a transient ischaemic attack, scored 0–7.

Respiratory

CURB-65

Severity of community-acquired pneumonia, scored 0–5, to guide site of care.

Centor Score (McIsaac modification)

Likelihood that a sore throat is group A streptococcal, scored −1 to 5.

Gastroenterology

Alvarado Score for Appendicitis

Probability of acute appendicitis from history, examination and white cell count, scored 0–10.

Glasgow-Blatchford Score

Need for intervention in upper gastrointestinal bleeding, scored 0–23.

Hepatology

MELD-Na

Sodium-adjusted MELD, the score used to rank liver transplant waiting lists.

Child-Pugh Score

Cirrhosis severity class A–C, still the basis of most drug labelling in liver disease.

FIB-4 Index

Non-invasive estimate of advanced liver fibrosis from age, transaminases and platelets.

Thrombosis

Wells Score for DVT

Pre-test probability of deep vein thrombosis, to direct D-dimer versus ultrasound.

Wells Score for PE

Pre-test probability of pulmonary embolism, to direct D-dimer versus CTPA.

Critical care

Glasgow Coma Scale

Eye, verbal and motor response, scored 3–15.

qSOFA

Three bedside signs that flag a patient with infection at risk of poor outcome.

APACHE II

ICU severity of illness from twelve physiological variables, age and chronic health.

Emergency & trauma

Parkland Formula for Burns

Crystalloid volume for the first 24 hours after a major burn.

Obstetrics & paediatrics

Apgar Score

Newborn condition at 1 and 5 minutes, scored 0–10.

Bishop Score

Cervical favourability before induction of labour, scored 0–13.

Paediatric Maintenance Fluids (4-2-1)

Hourly and daily maintenance fluid for a child, by the Holliday-Segar method.

Mental health

PHQ-9 Depression Scale

Severity of depressive symptoms over the last two weeks, scored 0–27.

GAD-7 Anxiety Scale

Severity of anxiety symptoms over the last two weeks, scored 0–21.

IQ Test (estimated)

A twenty-question reasoning test — number series, analogies and logic — scored to an estimated IQ with its percentile.

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Every formula here works out instantly in the browser, with its published source beside the result.

Educational use only — not medical advice. Never a substitute for clinical judgement.

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