iatroX Calculators provides 80+ clinical calculators — each with UK-guideline-referenced interpretation, clinical pearls, safety caveats, and cross-links to related tools in the clinical workflow. This guide maps the complete collection by specialty, with the NICE pathway each calculator connects to.
Cardiovascular
QRISK3 — 10-year CVD risk. NICE CG181: offer atorvastatin 20mg at ≥10%. CHA₂DS₂-VASc — AF stroke risk. NICE NG196: anticoagulate at ≥2 (male) / ≥3 (female). HAS-BLED — AF bleeding risk. Informs monitoring intensity, not anticoagulation withholding. HEART Score — Chest pain risk stratification. Low risk (0-3) → consider early discharge. GRACE Score — ACS mortality prediction. Informs angiography timing per NICE NG185. TIMI Score — ACS risk. Complements GRACE for NSTEMI risk stratification. Framingham — Historical CVD risk. Superseded by QRISK3 in UK practice but still referenced internationally.
Respiratory
CURB-65 — CAP severity. BTS/NICE: score 0-1 home treatment, 2 consider admission, 3+ consider ICU. CAT Score — COPD assessment. NICE NG115: combined with exacerbation frequency for GOLD classification. mMRC Dyspnoea Scale — Breathlessness grading. Used alongside CAT for COPD assessment.
Renal
CKD-EPI eGFR — Renal function staging. NICE NG203: referral at eGFR <30 or sustained decline ≥25%. Cockcroft-Gault — Creatinine clearance for drug dosing. BNF: specific drugs reference CrCl, not eGFR. KDIGO AKI Staging — Acute kidney injury severity. Stages 1-3 based on creatinine rise or urine output.
Gastroenterology and Hepatology
FIB-4 — Liver fibrosis screening. NICE NG49: <1.30 low risk, 1.30-2.67 indeterminate, >2.67 refer. NAFLD Fibrosis Score — Second-line fibrosis assessment for indeterminate FIB-4. Child-Pugh — Cirrhosis staging (A/B/C). Informs prognosis and management intensity. MELD / MELD-Na — End-stage liver disease severity. Transplant prioritisation. Glasgow-Blatchford — Upper GI bleed risk. Score 0 = consider outpatient management. Rockall Score — Post-endoscopy GI bleed mortality risk. Maddrey DF — Alcoholic hepatitis severity. ≥32 = consider prednisolone. Lille Score — Day 7 prednisolone response in alcoholic hepatitis.
Emergency and Critical Care
NEWS2 — Early warning score. RCP guidance: ≥5 triggers sepsis screening (NICE NG51), ≥7 emergency response. qSOFA — Quick sepsis screening. ≥2 = consider sepsis. SOFA — Sequential organ failure assessment. ICU severity scoring. APACHE II — ICU mortality prediction. Glasgow Coma Scale — Consciousness assessment. NIHSS — Stroke severity. Informs thrombolysis and thrombectomy decisions. ABCD2 — TIA stroke risk within 7 days.
VTE and Haematology
Wells PE — PE pre-test probability. NICE NG128: ≤4 → D-dimer, >4 → CTPA. Wells DVT — DVT pre-test probability. PERC Rule — PE rule-out in very low-risk patients. YEARS Algorithm — Streamlined PE pathway with variable D-dimer thresholds. sPESI — PE severity after diagnosis. Score 0 = consider outpatient management. Geneva Score (Revised) — Alternative to Wells PE. Objective criteria only. Age-Adjusted D-dimer — Threshold = age × 10 ng/mL for patients >50. Caprini Score — Surgical VTE risk assessment. Padua Score — Medical VTE risk assessment. IMPROVE Bleeding Risk — Balances thromboprophylaxis against bleeding risk.
Mental Health
PHQ-9 — Depression severity. NICE NG222 stepped care thresholds. GAD-7 — Anxiety severity. AUDIT-C — Alcohol screening. NICE PH24: ≥5 positive screen. C-SSRS — Suicide severity rating. Safety assessment when PHQ-9 item 9 is positive. Edinburgh PND Scale — Postnatal depression screening.
Obstetrics and Gynaecology
Bishop Score — Cervical favourability for induction of labour. EDD Calculator — Estimated due date from LMP or dating scan.
Paediatrics
PECARN — Paediatric head injury CT decision rule. Centile Calculators — Growth assessment.
Surgical and Trauma
Alvarado Score — Appendicitis probability. Ranson Criteria — Acute pancreatitis severity.
The iatroX Difference
Every calculator on iatroX maps to the UK guideline pathway — not just "score = X" but "score = X, which per NICE [guideline number] means [specific clinical action]." Cross-linked related calculators connect one tool to the next in the clinical workflow. Clinical pearls on every calculator highlight the practical considerations that source literature does not cover. No ads. Semantic search. Free.
Available at iatrox.com/calculators.