1,329 calculators and references across 60 specialties, with formula confidence shown up front.
UKPDS Risk based cardiac risk calculator: clinical explanation and context The UKPDS risk approach was developed from a large prospective cohort of people with type two diabetes followed during the United Kingdom Prospective Diabetes Study. The model incorporates age, sex, duration of diabetes, glycemic control, systolic blood pressure, lipid measures, smoking status, and markers of renal involvement to estimate the
UKPDS Risk based cardiac risk calculator: clinical explanation and context The UKPDS risk approach was developed from a large prospective cohort of people with type two diabetes followed during the United Kingdom Prospective Diabetes Study. The model incorporates age, sex, duration of diabetes, glycemic control, systolic blood pressure, lipid measures, smoking status, and markers of renal involvement to estimate the
Assessment of LV filling pressures in Atrial Fibrillation Recommendations for Cardiac Chamber Quantification by Echocardiography in Adults: An Update from the ASE and EACVI (2015)
Aorta View High Right Parasternal View of the Aorta Asc Ao : Ascending aorta, AV : Aortic valve.
Unloading Diuretic Response Index (UDRI): Explanation and Clinical Context The Unloading Diuretic Response Index (UDRI) is a clinical tool designed to quantify the effectiveness of loop diuretics in acute decompensated heart failure by adjusting for body weight and administered diuretic dose. It is calculated as the net fluid loss normalized to body weight and standard loop diuretic dose (usually per 40 mg IV furosem
Upper Extremity Functional Index Explanation and Clinical Context The Upper Extremity Functional Index is a patient reported outcome measure that assesses upper limb function. It is usually scored from 0 to 80 where higher values indicate better function. To use this tool enter the total raw score obtained from the UEFI questionnaire. The calculator converts the raw score into a normalized percentage of the maximum p
Urban Heat Island Cardio-Stress Adjuster: Rationale, Model, and Clinical Context This tool provides an evidence-informed estimate of incremental cardiovascular risk associated with ambient heat and the Urban Heat Island (UHI) effect. It is designed for public health planning, triage protocols during heat alerts, and patient counseling. The core signal comes from meta-analytic evidence that cardiovascular risk rises w
Urea Reduction Ratio URR Explanation and Clinical Context Urea Reduction Ratio is a standard measure of the adequacy of hemodialysis based on the reduction of blood urea nitrogen concentration before and after a dialysis session. URR reflects how effectively solute clearance is achieved during treatment. A higher URR indicates better dialysis efficiency. A value of sixty five percent or higher is generally accepted a
Explanation and Clinical Context This tool is designed for patients with non ST segment elevation acute coronary syndrome and helps clinicians identify situations in which an immediate invasive strategy with urgent coronary angiography is appropriate. The 2025 American guideline on acute coronary syndromes states that patients with NSTE ACS who have refractory angina or hemodynamic or electrical instability should un
Uric Acid Quartile Mortality Gradient: Explanation and Clinical Context This calculator stratifies patients into quartiles based on serum uric acid (UA) levels to estimate relative mortality risk. Quartile assignment (Q1–Q4) reflects population-based thresholds commonly reported in epidemiological studies. Higher uric acid levels have been associated with increased cardiovascular and all-cause mortality. The lowest q
Urine Sodium Na Urine Potassium K Urine Chloride Cl Urine Anion Gap Explanation and Clinical Context The urine anion gap is a practical bedside calculation that estimates urinary ammonium excretion. It is calculated using the sum of urine sodium and urine potassium minus urine chloride. Ammonium is excreted in association with chloride therefore low chloride relative to sodium and potassium suggests impaired ammonium