Essential clinical calculators including eGFR, creatinine clearance, corrected calcium, anion gap, serum osmolality, and more. These tools assist healthcare providers with quick bedside calculations using validated medical formulas.
This category currently includes 19 tools, including eGFR Calculator, Creatinine Clearance, and QTc Calculator.
These resources are built for clinicians, trainees, and medically informed patients who need fast bedside calculations. Use the results as decision support and pair them with full clinical context and local guidelines.
Calculate estimated glomerular filtration rate (eGFR) using the CKD-EPI 2021 race-free equation. Free kidney function assessment with CKD staging from serum creatinine.
Calculate creatinine clearance (CrCl) using the Cockcroft-Gault equation. Used for renal drug dosing adjustments based on kidney function.
Calculate corrected QT interval using Bazett, Fridericia, and Framingham formulas. Assess QT prolongation risk from ECG measurements.
Estimate blood alcohol concentration (BAC) from standard drinks, body weight, sex, and time since drinking started using a Widmark-style model. Screen for alcohol use disorder with [AUDIT](/tools/audit) or [CAGE Questionnaire](/tools/cage).
Calculate the MELD and MELD-Na scores to assess liver disease severity and transplant priority. Uses bilirubin, INR, creatinine, and sodium.
Calculate the Child-Pugh score to classify the severity of chronic liver disease and estimate prognosis. Uses bilirubin, albumin, INR, ascites, and encephalopathy.
Calculate the anion gap and albumin-corrected anion gap to help evaluate metabolic acidosis. Essential for the ER and ICU workup.
Calculate the alveolar-arterial oxygen gradient to evaluate the cause of hypoxemia. Differentiates lung pathology from hypoventilation.
Calculate corrected calcium adjusted for albumin levels. Essential for accurate interpretation of total calcium in hypoalbuminemic patients.
Interpret arterial blood gas (ABG) results to identify acid-base disorders. Determines primary disorder and compensation status from pH, pCO₂, and HCO₃⁻.
Estimate PaO₂ from SpO₂ pulse oximetry using the oxygen-hemoglobin dissociation curve. SpO₂ 98%≈100 mmHg, 95%≈80, 90%≈60 (critical threshold). Useful when ABG is unavailable.
Convert laboratory values between conventional (US) and SI (international) units for 20+ common tests including creatinine, glucose, cholesterol, hemoglobin, electrolytes, and thyroid function.
Calculate corrected sodium level for hyperglycemia using the Katz formula. Essential for evaluating true sodium status in patients with elevated glucose.
Calculate Mean Arterial Pressure (MAP = DBP + ⅓ × pulse pressure). Normal MAP: 70–100 mmHg. Sepsis target: MAP ≥65 mmHg. MAP <60 mmHg indicates inadequate organ perfusion requiring immediate intervention.
Calculate expected pCO₂ for respiratory compensation in metabolic acidosis using Winter's formula: expected pCO₂ = 1.5 × [HCO₃] + 8 ± 2. Compare to actual pCO₂ to identify concurrent respiratory disorders.
Calculate serum osmolality from sodium, glucose, and BUN. Normal range: 275–295 mOsm/kg. Osmolal gap >10 suggests toxic alcohol ingestion (methanol, ethylene glycol, isopropanol) or other unmeasured osmoles.
Calculate adjusted body weight (AdjBW) for drug dosing in obese patients: AdjBW = IBW + 0.4 × (TBW − IBW). Used for aminoglycosides, vancomycin, and other weight-based medications when actual weight exceeds IBW by >20%.
Calculate corrected sodium in hyperglycemia using the Katz formula: add 1.6 mEq/L per 100 mg/dL glucose above normal. Essential in DKA to reveal true sodium status hidden by osmotic dilution from hyperglycemia.
Calculate the transtubular potassium gradient (TTKG) to evaluate renal potassium handling. TTKG >7–8 in hypokalemia suggests urinary potassium wasting; TTKG <5 in hyperkalemia indicates renal tubular dysfunction or hypoaldosteronism.