eGFR =
39.8 x [ht/Scr]0.456 x [1.8/cysC]0.418 x [30/BUN]0.079 x [1.076male] [1.00female] x [ht/1.4]0.179

Abbreviations / Units

eGFR (estimated glomerular filtration rate) = mL/min/1.73 m2

BUN (blood urea nitrogten) = mg/dL

cysC (cystatin C) = mg/L

ht (height) = meters

Scr (standardized serum creatinine) = mg/dL


Clinical Use

  • For use in children 1-18 years old.
  • May be useful as a confirmatory test in specific circumstances when eGFR based on serum creatinine is less accurate, or when the clinical scenario warrants a secondary test.
  • In most cases, the Bedside Schwartz equation [0.413(ht/cm/Scr)] allows rapid and reasonably accurate estimation of GFR for clinical use in children with CKD. When measurement and calibration is more broadly available, GFR estimates using cystatin C may also have broad clinical utility.


  1. Schwartz GJ, Schneider MF, Maier PS, et al. Improved equations estimating GFR in children with chronic kidney disease using an immunonephelometric determination of cystatin C. Kidney Int. 2012;82(4):445-453.
  2. Grubb A, Blirup-Jensen S, Lindstrom V, Schmidt C, Althaus H, Zegers I. First certified reference material for cystatin C in human serum ERM-DA471/IFCC. Clin Chem Lab Med. 2010;48(11):1619-1621.