Nephrology
21 calculators
Kidney function estimation, renal replacement therapy adequacy, electrolyte handling, and acute kidney injury assessment.
Related Specialties
CKD-EPI 2021 eGFR Equation
Estimates glomerular filtration rate (eGFR) using the 2021 CKD-EPI creatinine equation.
Internal MedicineCockcroft-Gault Equation
Estimates creatinine clearance (CrCl) for medication dosing using the Cockcroft-Gault equation.
Internal MedicineBUN/Creatinine Ratio
Calculates the Blood Urea Nitrogen to Creatinine ratio to help differentiate causes of kidney dysfunction.
Internal MedicineMDRD GFR Equation
Estimates glomerular filtration rate using the 4-variable MDRD equation.
Internal MedicineAlbumin-to-Creatinine Ratio
Calculates urine albumin-to-creatinine ratio (ACR) for CKD screening and staging.
NephrologyFractional Excretion of Sodium (FENa)
Calculates the fractional excretion of sodium to distinguish prerenal azotemia from acute tubular necrosis.
Internal MedicineFractional Excretion of Urea (FEUrea)
Calculates the fractional excretion of urea for renal evaluation, particularly useful when diuretics are present.
Internal MedicineTranstubular Potassium Gradient (TTKG)
Calculates the transtubular potassium gradient to assess renal potassium handling.
Internal MedicineCalcium-Phosphate Product
Calculates the calcium-phosphate product used in renal risk assessment for vascular calcification.
Internal MedicineFractional Excretion of Uric Acid (FEUA)
Calculates the fractional excretion of uric acid (FEUA) to help distinguish prerenal azotemia from intrinsic renal injury in acute kidney injury, and to assess uric acid handling (e.g., SIADH, tumor lysis, Fanconi syndrome).
Internal MedicineFractional Excretion of Phosphate (FEP)
Calculates the fractional excretion of phosphate (FEP) to localize the cause of hypophosphatemia: a high FEP indicates renal phosphate wasting, whereas a low FEP suggests redistribution or extrarenal loss.
Internal MedicineFractional Excretion of Calcium (FECa / Calcium–Creatinine Clearance Ratio)
Calculates the fractional excretion of calcium (calcium–creatinine clearance ratio, CCCR) to help distinguish familial hypocalciuric hypercalcemia (FHH) from primary hyperparathyroidism in patients with hypercalcemia and non-suppressed PTH.
Internal MedicineRenal Failure Index (RFI)
Calculates the renal failure index (RFI), a classic urinary index that uses urine sodium relative to the urine:plasma creatinine ratio to help distinguish prerenal azotemia from acute tubular necrosis (ATN).
Internal MedicineUrine Osmolal Gap (UOG)
Calculates the urine osmolal gap — the difference between measured and estimated urine osmolality — to detect unmeasured osmoles in the urine (e.g., ethylene glycol, mannitol, or other toxins).
Internal MedicineFree Water Clearance (CH₂O)
Calculates renal free water clearance (CH₂O) from urine flow, urine osmolality, and plasma osmolality to characterize renal water handling in polyuria, hyponatremia, and hypernatremia.
Internal MedicineElectrolyte-Free Water Clearance (EFWC)
Calculates urinary electrolyte-free water clearance (EFWC) from urine flow and urinary/plasma sodium and potassium. It is used to distinguish renal from extrarenal water losses and to guide fluid therapy in dysnatremia.
Internal MedicineUrine Protein-to-Creatinine Ratio (UPCR)
Calculates the urine protein-to-creatinine ratio (UPCR) from a spot urine sample to estimate 24-hour proteinuria for CKD detection, monitoring, and nephrotic range proteinuria screening.
Internal MedicineCreatinine Clearance from 24-Hour Urine (CrCl)
Calculates creatinine clearance from a 24-hour urine collection using urine creatinine, serum creatinine, and 24-hour urine volume. It is the classic timed-collection estimate of GFR.
NephrologyUrine Anion Gap (UAG)
Calculates the urine anion gap: UAG = (urine sodium + urine potassium) − urine chloride. It is used to distinguish renal from extrarenal (gastrointestinal) causes of a normal anion gap (hyperchloremic) metabolic acidosis with hypokalemia and normal renal function.
Internal MedicineKt/V (Daugirdas Second Generation spKt/V)
Calculates single-pool Kt/V (spKt/V) for hemodialysis adequacy using the Daugirdas second-generation formula. KDOQI defines a minimum delivered spKt/V of 1.2 per treatment for patients treated three times weekly, with a target of 1.4.
NephrologyKDIGO AKI Staging
Classifies acute kidney injury (AKI) severity using the KDIGO 2012 criteria based on serum creatinine changes and urine output. The highest applicable stage is assigned when multiple criteria are met.
Nephrology