General Medical Calculators
Essential general medical calculators for anthropometric measurements, fluid management, and basic clinical formulas.
Why This Matters
Anthropometric measurements including BMI, BSA, and ideal body weight are fundamental clinical tools used across all medical specialties. They guide drug dosing, nutritional assessment, and surgical planning. Electrolyte calculations (anion gap, corrected calcium, corrected sodium) are critical for acid-base and electrolyte disorder diagnosis. These calculators are among the most frequently used tools in daily clinical practice.
When to Use
Use BMI for obesity screening and nutritional assessment. Use BSA for chemotherapy dosing and cardiac index calculations. Use Ideal Body Weight for drug dosing and ventilator settings. Use BMR/Mifflin-St Jeor for caloric needs assessment. Use anion gap, corrected calcium, and corrected sodium for metabolic and electrolyte disorders.
Available General Medicine Calculators
BMI
The Body Mass Index (BMI) is a simple, widely used measurement that estimates body fat based on height and weight. It is used as a screening tool for weight categories that may lead to health problems.
Calculate →BSA
Body Surface Area (BSA) is a measurement of the total surface area of the human body used in many medical contexts including chemotherapy dosing, cardiac output indexing, and burn management.
Calculate →Ideal Body Weight
Ideal Body Weight (IBW) estimates the optimal weight for an individual based on height and sex. It is commonly used for drug dosing, ventilator settings, and nutritional assessment.
Calculate →Anion Gap
The anion gap is a calculated value derived from serum electrolytes that helps differentiate types of metabolic acidosis and identify underlying causes.
Calculate →Metabolic Rate
Basal Metabolic Rate (BMR) is the number of calories your body needs at complete rest. Total Daily Energy Expenditure (TDEE) adjusts BMR for physical activity levels.
Calculate →Corrected Calcium
Corrected calcium adjusts total serum calcium for albumin levels to more accurately reflect the true ionized calcium status in patients with abnormal albumin.
Calculate →MAP / Shock Index
Mean Arterial Pressure (MAP) is the average blood pressure in the arterial system during one cardiac cycle. The Shock Index (HR/SBP) is an early marker of hemodynamic instability.
Calculate →BMD T-Score
The World Health Organization (WHO) classification of bone mineral density (BMD) T-scores provides standardized diagnostic criteria for osteoporosis and defines categories of fracture risk.
Calculate →Fluid Deficit
This calculator estimates total body water deficit based on estimated dehydration percentage and provides maintenance fluid rate and replacement recommendations for adult patients.
Calculate →Corrected Na
Hyperglycemia causes a factitious lowering of measured serum sodium due to the osmotic shift of water from the intracellular to the extracellular space. The corrected sodium formula estimates what the sodium would be if glucose were normal.
Calculate →PEF Calculator
The Peak Expiratory Flow (PEF) predicted calculator estimates the expected PEF value based on age, gender, and height using Nunn and Gregg reference equations for asthma monitoring.
Calculate →Alvarado Score
The Alvarado score is a clinical scoring system used to estimate the probability of acute appendicitis in patients presenting with right lower quadrant abdominal pain, helping guide diagnostic and management decisions.
Calculate →MELD Score
The MELD (Model for End-Stage Liver Disease) score is a validated scoring system for assessing the severity of chronic liver disease and prioritizing patients for liver transplantation. It predicts 3-month mortality risk using bilirubin, INR, and creatinine.
Calculate →Serum Osmolality
Calculated serum osmolality and osmolal gap help evaluate hyponatremia, hypernatremia, and detect toxic alcohol ingestion (methanol, ethylene glycol, isopropyl alcohol).
Calculate →CCI Score
The Charlson Comorbidity Index (CCI) is a validated prognostic tool that predicts 10-year mortality based on the presence and severity of 19 comorbid conditions, with age adjustment. It is one of the most widely used comorbidity indices in clinical research and practice.
Calculate →ANC
The Absolute Neutrophil Count (ANC) is a critical laboratory value used to quantify the number of neutrophils available for fighting infection. It is essential for assessing neutropenia severity, guiding chemotherapy dosing, determining febrile neutropenia risk, and deciding on growth factor support (G-CSF) therapy.
Calculate →Retic Index
The Reticulocyte Production Index (RPI) is a corrected measurement of reticulocyte count that accounts for the degree of anemia and the maturation shift of reticulocytes. It provides a more accurate assessment of bone marrow erythropoietic activity than the raw reticulocyte percentage.
Calculate →TSAT
Transferrin saturation (TSAT) is a key laboratory value that measures the percentage of iron-binding sites on transferrin that are occupied by iron. It is essential for diagnosing and monitoring iron deficiency, iron overload, and guiding iron replacement therapy.
Calculate →ECOG PS
The ECOG Performance Status (ECOG PS) scale, developed by the Eastern Cooperative Oncology Group, is a widely used tool for assessing a patient's functional capacity and ability to perform daily activities. It is a standard measure in oncology for treatment decision-making and clinical trial eligibility.
Calculate →Karnofsky Score
The Karnofsky Performance Scale (KPS) is a widely used 11-point scale (0-100) that quantifies a patient's functional status and ability to perform activities of daily living. It is commonly used in oncology, palliative care, and geriatrics.
Calculate →IPSS Score
The International Prostate Symptom Score (IPSS) is a validated 7-question screening tool used to assess the severity of lower urinary tract symptoms (LUTS) in men with benign prostatic hyperplasia (BPH) and monitor treatment response.
Calculate →Morse Fall Scale
The Morse Fall Scale is a validated fall risk assessment tool used to identify hospitalized patients at risk of falling, assessing six domains: history of falls, secondary diagnoses, ambulatory aids, IV therapy, gait, and mental status.
Calculate →G8
The Geriatric 8 (G8) screening tool is an 8-item validated instrument designed to identify older patients who may benefit from comprehensive geriatric assessment (CGA). It is widely used in geriatric oncology to detect frailty.
Calculate →MNA-SF
The Mini Nutritional Assessment Short Form (MNA-SF) is a validated 6-item screening tool for malnutrition risk in older adults. It is widely used in geriatric medicine, long-term care, and hospital settings to identify patients requiring nutritional intervention.
Calculate →PSQI
The Pittsburgh Sleep Quality Index (PSQI) is a self-rated questionnaire that assesses sleep quality and disturbances over a 1-month time interval. It is the most widely used standardized measure of sleep quality in clinical research and practice.
Calculate →BI-RADS
The Breast Imaging Reporting and Data System (BI-RADS) is a standardized classification system developed by the American College of Radiology (ACR) for reporting mammography, ultrasound, and MRI findings of the breast. It provides clear assessment categories, malignancy risk ranges, and management recommendations to ensure consistent interpretation and communication of breast imaging results.
Calculate →PI-RADS
The Prostate Imaging Reporting and Data System (PI-RADS) is a standardized classification system for multiparametric MRI of the prostate, developed by the American College of Radiology, European Society of Urogenital Radiology, and the AdME Tech Foundation. It provides a framework for reporting prostate MRI findings with clear assessment categories for the likelihood of clinically significant prostate cancer.
Calculate →LACE
The LACE Index predicts the risk of unplanned 30-day hospital readmission or death. It combines Length of stay, Acuity of admission, Comorbidity (Charlson), and Emergency department visits in the prior 6 months into a single validated risk score.
Calculate →HOSPITAL
The HOSPITAL score predicts the risk of 30-day potentially avoidable hospital readmissions using 8 clinical variables. It was designed to identify patients at high risk for readmissions that might be prevented better transitional care.
Calculate →
Clinical Guidelines
- WHO Classification of Overweight and Obesity (2024)
- AACE/ACE Clinical Practice Guidelines for Obesity Management (2024)
- Harrison's Principles of Internal Medicine, 22nd Edition — Fluid and Electrolyte Disorders
- KDIGO Guidelines for Electrolyte Disorders (2024)
Frequently Asked Questions
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