Health & Clinical Calculators

Clinically validated calculators with formulas cited to original journals (NEJM, JAMA, Circulation, etc.). Educational reference; not medical advice.

All tools

10

A1c to eAG (Estimated Average Glucose) Calculator

Convert HbA1c (%) to estimated average glucose: eAG (mg/dL) = 28.7 × A1c − 46.7. ADAG / Nathan 2008.

eAG (Average Glucose) to A1c Calculator

Convert estimated average glucose back to HbA1c: A1c (%) = (eAG + 46.7) / 28.7. ADAG / Nathan 2008 inverse.

eGFR (CKD-EPI 2021, race-free) Calculator

eGFR from creatinine, age, sex per CKD-EPI 2021 (Inker et al., NEJM). Race-free formula adopted by NKF/ASN.

LDL Cholesterol (Friedewald) Calculator

LDL = TC − HDL − TG/5 (mg/dL). Friedewald 1972 Clin Chem. Not valid if triglycerides > 400 mg/dL.

MELD-Na Score Calculator (Liver Allocation)

MELD-Na = MELD + 1.32 × (137 − Na) − [0.033 × MELD × (137 − Na)]. UNOS 2016 update; Kim 2008 NEJM.

CHA₂DS₂-VASc Score Calculator (Stroke Risk in AF)

Stroke-risk score in non-valvular atrial fibrillation. Lip 2010 Chest. ESC/AHA recommend OAC if score ≥2 (men) / ≥3 (women).

Wells Score Calculator (Pulmonary Embolism)

Wells PE score — pretest probability for pulmonary embolism. Wells 2000 Annals Intern Med (modified).

CURB-65 Calculator (Pneumonia Severity)

CURB-65 = Confusion + Urea>7 + RR≥30 + BP<90/60 + Age≥65. Lim 2003 Thorax. Predicts 30-day pneumonia mortality.

Framingham 10-Year CVD Risk Calculator

10-year general cardiovascular disease risk per D'Agostino 2008 Circulation. Sex-specific, lab-based.

FRAX-Style Fracture Risk Estimator (Educational)

Approximate 10-year major osteoporotic & hip fracture risk from age, sex, BMD T-score, and clinical risk factors. Educational only — for clinical use, see frax.shef.ac.uk/FRAX.