Renal function tools including eGFR (CKD-EPI), creatinine clearance (Cockcroft-Gault), FENa, BUN/creatinine ratio, free water deficit, urine anion gap, and transtubular potassium gradient. For evaluating kidney function and electrolyte disorders.
This category currently includes 5 tools, including FENa Calculator, BUN/Cr Ratio, and Free Water Deficit.
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 the Fractional Excretion of Sodium (FENa) to differentiate pre-renal azotemia (FENa <1%) from intrinsic renal disease such as ATN (FENa >2%) in acute kidney injury.
Calculate the BUN/Creatinine ratio to distinguish pre-renal from intrinsic acute kidney injury. Normal ratio 10–20. Ratio >20 suggests pre-renal azotemia; <10 suggests intrinsic renal disease.
Calculate free water deficit for hypernatremia using TBW × (serum Na/140 − 1). Includes safe correction rate guidance: ≤10–12 mEq/L per 24h to avoid cerebral edema.
Calculate the urine anion gap to differentiate GI from renal causes of non-anion gap metabolic acidosis. Negative UAG suggests GI bicarbonate loss; positive UAG suggests renal tubular acidosis.
Calculate measured creatinine clearance from a 24-hour urine collection. More accurate than estimated GFR in certain populations.