maratoolMedical calculators
Free medical calculators, clinical scores, and bedside scales. For educational use by healthcare professionals — runs in your browser, nothing leaves your device.
Specialty
BMI Calculator
Calculate Body Mass Index (BMI) and body surface area from weight and height. Includes BMI classification.
Mean Arterial Pressure (MAP) Calculator
Calculate mean arterial pressure (MAP) from systolic and diastolic blood pressure.
Ideal Body Weight Calculator
Calculate ideal body weight by height using the Devine, Robinson, Miller, and Hamwi formulas.
Corrected QT Interval (QTc) Calculator
Calculate corrected QT (QTc) using Bazett, Fridericia, Framingham, and Hodges formulas.
Friedewald LDL Cholesterol Calculator
Calculate LDL cholesterol using the Friedewald formula from total cholesterol, HDL, and triglycerides.
Parkland Burn Formula Calculator
Calculate fluid resuscitation volume for burn patients using the Parkland formula.
Estimated Average Glucose (eAG) from HbA1c
Convert HbA1c percentage to estimated average glucose (eAG) in mg/dL and mmol/L.
CAM-ICU Delirium Assessment
Confusion Assessment Method for the ICU (CAM-ICU) for delirium screening in critically ill patients.
GINA Asthma Control Classification (2025)
Classify asthma control using the GINA 2025 criteria (well-controlled, partly controlled, uncontrolled).
CAGE Alcohol Screening Test
CAGE questionnaire for alcohol use disorder screening (4 questions).
Serum-Ascites Albumin Gradient (SAAG)
Calculate SAAG to differentiate portal hypertensive from non-portal hypertensive ascites.
Transferrin Saturation (TSAT) Calculator
Calculate transferrin saturation index from serum iron and total iron-binding capacity (TIBC).
Mini-Mental State Examination (MMSE)
Score cognitive function with the 30-point Mini-Mental State Examination.
Lille Model for Alcoholic Hepatitis
Predict 6-month mortality in alcoholic hepatitis patients on steroid therapy using the Lille model.
Covid-19 Severity Protocol
Stratify Covid-19 severity by clinical and laboratory criteria.
Fagerström Test for Nicotine Dependence
Assess nicotine dependence severity with the Fagerström Test (6 questions).
Estimated Blood Volume Calculator
Estimate total blood volume by weight, height, and sex (Nadler formula).
CKD-EPI Creatinine Clearance Calculator
Estimate glomerular filtration rate (eGFR) using the 2021 CKD-EPI creatinine equation.
Cockcroft-Gault Creatinine Clearance Calculator
Estimate creatinine clearance using the Cockcroft-Gault formula.
MDRD GFR Calculator
Estimate glomerular filtration rate using the 4-variable MDRD equation.
Fractional Excretion of Sodium (FENa)
Differentiate prerenal from intrinsic acute kidney injury using FENa.
Fractional Excretion of Urea (FEUrea)
FEUrea for AKI workup in patients on diuretics where FENa is unreliable.
Urine Protein-to-Creatinine Ratio (UPCR)
Calculate UPCR from a single urine sample to estimate 24-hour protein excretion.
Bicarbonate Deficit Calculator
Calculate bicarbonate replacement dose for severe metabolic acidosis.
Gestational Age by LMP Calculator
Calculate gestational age and estimated due date from last menstrual period (Naegele rule).
Gestational Age by Ultrasound Calculator
Calculate gestational age and due date from ultrasound biometry.
APGAR Score Calculator
Calculate the APGAR score at 1 and 5 minutes for newborn assessment.
Pediatric Glasgow Coma Scale
Pediatric-adapted Glasgow Coma Scale for infants and children.
Pediatric Endotracheal Tube Size Calculator
Estimate uncuffed and cuffed ETT size and depth by age in children.
Pediatric Infusion Calculator (mcg/kg/min)
Pediatric drug infusion rate calculator in mcg/kg/min.
Pediatric Infusion Calculator (mg/kg/hour)
Pediatric drug infusion rate calculator in mg/kg/hour.
Finnegan Neonatal Abstinence Score
Score severity of neonatal abstinence syndrome using the Finnegan scale.
Raimondi Coma Scale (Pediatric)
Pediatric coma scale by Raimondi for assessing consciousness in infants and children.
Rodwell Score for Neonatal Sepsis
Score for screening neonatal sepsis using hematologic criteria.
Capurro Gestational Age (Somatic)
Estimate gestational age in newborns using somatic features (Capurro method).
Capurro Gestational Age (Neurological)
Estimate gestational age in newborns using neurological features (Capurro method).
Serum Osmolality Calculator
Calculate serum osmolality from sodium, glucose, and BUN.
Calcium Correction for Albumin
Correct total serum calcium for hypoalbuminemia.
Sodium Correction for Hyperglycemia
Correct serum sodium for hyperglycemia (Katz / Hillier formulas).
Total Iron Deficit Calculator (Ganzoni)
Calculate total body iron deficit for IV iron replacement using the Ganzoni formula.
Benzodiazepine Equivalence Calculator
Convert between benzodiazepine doses (diazepam, lorazepam, alprazolam, clonazepam, etc.).
Corticosteroid Conversion Calculator
Convert between corticosteroid doses (prednisone, dexamethasone, hydrocortisone, etc.).
Opioid Conversion Calculator
Convert between opioid doses to morphine milligram equivalents (MME).
Rapid Sequence Intubation (RSI) Dose Calculator
Calculate induction and paralytic doses for rapid sequence intubation by weight.
Phenytoin Total Serum Level Calculator
Correct total phenytoin level for albumin and renal function (Sheiner-Tozer).
Drops/min to mL/hour Converter
Convert IV drip rate from drops per minute (gtt/min) to mL/hour and vice versa.
mcg/kg/min to mL/hour Converter
Convert drug infusion rate between mcg/kg/min and mL/hour for vasoactive drugs.
Ideal PaO2 by Age Calculator
Estimate the expected normal PaO2 based on patient age.
PaO2/FiO2 Ratio Calculator (ARDS)
Calculate the PaO2/FiO2 ratio (P/F ratio) and classify ARDS severity by Berlin criteria.
SpO2/FiO2 Ratio Calculator
Calculate SpO2/FiO2 ratio and equivalence to PaO2/FiO2 for non-invasive ARDS assessment.
FOUR Score Coma Scale
Full Outline of UnResponsiveness (FOUR) score for coma assessment.
Fisher Scale for Subarachnoid Hemorrhage
Grade subarachnoid hemorrhage by CT scan appearance using the Fisher scale.
Glasgow Coma Scale with Pupil Response (GCS-P)
Glasgow Coma Scale with pupil reactivity score (GCS-P).
Lawton IADL Scale
Lawton Instrumental Activities of Daily Living scale for functional assessment in elderly.
Ramsay Sedation Scale
Ramsay scale for level of sedation assessment (1–6).
RASS Scale (Richmond Agitation-Sedation)
Richmond Agitation-Sedation Scale (RASS) for ICU sedation assessment.
SAS Sedation Scale (Riker)
Riker Sedation-Agitation Scale (SAS) for ICU sedation.
CCS Angina Grading Scale
Canadian Cardiovascular Society (CCS) functional classification of angina pectoris.
Aldrete Recovery Score
Aldrete and Kroulik post-anesthesia recovery score.
ECOG Performance Status
Eastern Cooperative Oncology Group performance status scale (0–5).
Karnofsky Performance Scale (KPS)
Karnofsky Performance Status scale (0–100) for assessing oncology patient function.
Palliative Performance Scale (PPS)
Palliative Performance Scale (PPS) for hospice and palliative care prognosis.
Tokuhashi Score for Spinal Metastasis
Revised Tokuhashi score for prognosis in metastatic spinal disease.
Tomita Score for Spinal Metastasis
Tomita score for surgical strategy in spinal metastasis.
Palliative Prognostic Score (PaP)
PaP score for 30-day survival probability in palliative cancer patients.
Palliative Prognostic Index (PPI)
Palliative Prognostic Index for predicting survival in terminal cancer patients.
Pack-Year Smoking Calculator
Calculate cumulative cigarette smoking exposure in pack-years.
Candida Score
Candida Score for identifying ICU patients who may benefit from antifungal therapy.
CHADS2 Score
CHADS2 score for stroke risk in non-valvular atrial fibrillation.
NYHA Functional Classification
New York Heart Association functional classification of heart failure.
GELF Criteria for Follicular Lymphoma
GELF criteria for high tumor burden in follicular lymphoma.
DAS-28 CRP (Rheumatoid Arthritis)
Disease Activity Score (28 joints) with CRP for rheumatoid arthritis activity.
DAS-28 ESR (Rheumatoid Arthritis)
Disease Activity Score (28 joints) with ESR for rheumatoid arthritis activity.
ABCD2 Score for TIA
ABCD2 score for stroke risk after transient ischemic attack.
AIMS65 Score (Upper GI Bleed)
AIMS65 score for predicting in-hospital mortality in upper GI bleeding.
APACHE II Score
Acute Physiology and Chronic Health Evaluation II (APACHE II) for ICU mortality.
BISAP Score (Pancreatitis Mortality)
Bedside Index for Severity in Acute Pancreatitis (BISAP) for mortality risk.
Clinical Pulmonary Infection Score (CPIS)
CPIS for diagnosis of ventilator-associated pneumonia.
CRUSADE Bleeding Score
CRUSADE score for in-hospital major bleeding risk after NSTEMI.
CURB-65 Pneumonia Severity Score
CURB-65 score for community-acquired pneumonia severity and mortality risk.
Alvarado Score for Appendicitis
Alvarado score for clinical probability of acute appendicitis.
Caprini DVT Risk Score
Caprini Risk Assessment for venous thromboembolism in surgical patients.
Modified Centor Score (Strep Pharyngitis)
Modified Centor score for streptococcal pharyngitis probability.
CHA2DS2-VASc Score
CHA2DS2-VASc score for stroke risk in non-valvular atrial fibrillation.
Child-Pugh Score (Cirrhosis)
Child-Pugh score for prognosis of chronic liver disease and cirrhosis.
NAFLD Fibrosis Score
Non-alcoholic fatty liver disease (NAFLD) fibrosis score.
Framingham Risk Score
10-year cardiovascular disease risk by Framingham equations.
Khorana Score (VTE Risk in Cancer)
Khorana score for predicting chemotherapy-associated VTE risk.
Lee Revised Cardiac Risk Index (RCRI)
Lee RCRI for preoperative cardiac risk in non-cardiac surgery.
Maddrey Discriminant Function
Maddrey discriminant function for severity of alcoholic hepatitis.
Mayo Score for Ulcerative Colitis
Mayo Score for assessing ulcerative colitis disease activity.
Padua Prediction Score
Padua score for VTE risk in hospitalized medical patients.
Ranson Criteria for Acute Pancreatitis
Ranson Criteria for mortality in acute pancreatitis (admission and 48h).
RoPE Score (Paradoxical Embolism)
Risk of Paradoxical Embolism (RoPE) score for cryptogenic stroke with PFO.
Rockall Score (Upper GI Bleed)
Rockall score for mortality risk in upper gastrointestinal bleeding.
San Francisco Syncope Rule
San Francisco Syncope Rule for predicting serious outcomes after syncope.
ASPECTS Score (Stroke CT)
Alberta Stroke Program Early CT Score (ASPECTS) for early ischemic changes in stroke.
Wells Score for Pulmonary Embolism
Wells criteria for clinical probability of pulmonary embolism.
Wells Score for DVT
Wells criteria for clinical probability of deep vein thrombosis.
FIB-4 Index
FIB-4 index for non-invasive liver fibrosis assessment.
HAS-BLED Score
HAS-BLED bleeding risk score for patients on anticoagulation for AF.
HEART Score
HEART Score for major adverse cardiac events in chest pain patients.
MELD & MELD-Na Score
Model for End-Stage Liver Disease (MELD) and MELD-Na scores for cirrhosis prognosis.
NEWS 2 Score
National Early Warning Score 2 (NEWS 2) for clinical deterioration detection.
NIHSS Stroke Scale
National Institutes of Health Stroke Scale (NIHSS) for stroke severity.
Pneumonia Severity Index (PSI/PORT)
Pneumonia Severity Index (PSI/PORT) for mortality risk in community-acquired pneumonia.
qSOFA Score
Quick Sepsis-Related Organ Failure Assessment (qSOFA) for sepsis screening.
Sepsis-Induced Coagulopathy (SIC) Score
SIC score for diagnosing sepsis-induced coagulopathy.
SOFA Score
Sequential Organ Failure Assessment (SOFA) score for ICU organ dysfunction.
TIMI Risk Score (STEMI)
TIMI Risk Score for ST-elevation myocardial infarction (STEMI).
TIMI Risk Score (NSTEMI / UA)
TIMI Risk Score for non-ST-elevation MI and unstable angina.
GRACE Score (ACS)
GRACE score for in-hospital and 6-month mortality in acute coronary syndrome.
DKA Severity Calculator
Classify diabetic ketoacidosis severity (mild, moderate, severe).
SCORAD Index (Atopic Dermatitis)
SCORAD Index for severity of atopic dermatitis.
PASI Score (Psoriasis Severity)
Psoriasis Area and Severity Index (PASI) for psoriasis severity assessment.
PESI Score (Pulmonary Embolism Severity)
Pulmonary Embolism Severity Index (PESI) for 30-day mortality.
Pediatric Dehydration Severity
Severity assessment for dehydration in children to guide rehydration therapy.
Malignant Hyperthermia Score
Clinical Grading Scale for likelihood of malignant hyperthermia.
CDAI (Crohn's Disease Activity Index)
Crohn's Disease Activity Index (CDAI) for assessing Crohn's disease activity.
Bishop Score (Cervical Ripening)
Bishop score for predicting successful labor induction.
UCEIS (Ulcerative Colitis Endoscopic Index)
Ulcerative Colitis Endoscopic Index of Severity (UCEIS).
Detsky Cardiac Risk Index
Detsky modified multifactorial cardiac risk index for non-cardiac surgery.
Goldman Cardiac Risk Index
Goldman multifactorial cardiac risk index for non-cardiac surgery.
Harvey-Bradshaw Index (Crohn's)
Harvey-Bradshaw Index for Crohn's disease activity (simplified CDAI).
Injury Severity Score (ISS)
Injury Severity Score (ISS) for trauma anatomical severity.
Simplified PESI Score
Simplified PESI (sPESI) for pulmonary embolism 30-day mortality.
R-ISS Score (Multiple Myeloma)
Revised International Staging System for multiple myeloma prognosis.
PERC Rule (Pulmonary Embolism)
Pulmonary Embolism Rule-out Criteria (PERC) to safely exclude PE.
GWTG-HF Risk Score
Get With The Guidelines Heart Failure (GWTG-HF) in-hospital mortality risk.
MASCC Risk Index (Febrile Neutropenia)
MASCC risk index for low-risk febrile neutropenia in cancer patients.
TASH Score (Massive Transfusion)
Trauma Associated Severe Hemorrhage (TASH) score for massive transfusion prediction.
About these medical calculators
This page collects clinical scores, scales, and equations that clinicians use at the bedside or in the office to support a decision — risk stratification, severity grading, dosing references, screening, and triage. Most are direct implementations of the original published instruments, kept faithful to the source so the output you see here matches what a colleague would compute by hand.
What is on this page
The calculators cover several common needs. Risk stratification scores answer "how worried should I be" for a given patient — for example, CHA2DS2-VASc for stroke risk in atrial fibrillation, the Framingham risk score for ten-year cardiovascular events, and qSOFA for suspected sepsis outside the ICU. Severity and staging tools like MELD/MELD-Na for end-stage liver disease and NIHSS for acute stroke help quantify how sick a patient is and inform escalation or transplant prioritization. Renal function tools like CKD-EPI estimate GFR for staging chronic kidney disease and adjusting drug doses. General-purpose calculators such as the BMI calculator are included for screening and documentation.
Which to use when
Calculators on this site are filtered by specialty so you can narrow to cardiology, nephrology, hepatology, neurology, infectious diseases, and so on. Use the score whose inclusion criteria match your patient — many calculators are validated only in a specific population (for example, qSOFA outside the ICU, MELD-Na in candidates already meeting transplant criteria). Each calculator page lists the underlying reference and the interpretation thresholds the original authors published.
Educational use and privacy
These calculators are intended for educational and reference use by clinicians, residents, and students. They do not replace clinical judgment, do not constitute medical advice, and should not be used as the sole basis for diagnostic or treatment decisions for any individual patient. All computation happens in your browser — no inputs, results, or patient identifiers are transmitted, logged, or stored on any server.