Weill Cornell Medicine Care Discover Teach
Weill Cornell Medicine — Pediatric Critical Care Medicine

Creatinine Clearance — Schwartz Estimate

All calculations should be independently verified prior to clinical use. These calculators are intended to supplement, not replace, clinical judgment.

Estimate glomerular filtration rate (creatinine clearance) from serum creatinine and height using the original Schwartz method. Select the appropriate proportionality constant (k) for the patient's age and sex, or enter a custom value.

Important: This formula should not be used with serum creatinine values calibrated by isotope dilution mass spectrometry (IDMS). Use the Revised Schwartz Estimate for IDMS-calibrated creatinine measurements.
Patient category k
0.33
0.45
0.55
0.70
mg/dL
mL/min/1.73 m²

The original Schwartz formula estimates GFR from height and serum creatinine alone, without a timed urine collection:

CrCl = ( k × Ht ) ÷ Crserum

Height is in cm and serum creatinine is in mg/dL. The proportionality constant k reflects differences in muscle mass by age and sex. Serum creatinine must be at steady state for the estimate to be valid.

This formula tends to overestimate actual CrCl and should be used with caution. The National Kidney Disease Education Program recommends that GFR estimates above 75 mL/min/1.73 m² not be reported as an exact number. Many medications require dose adjustment when CrCl falls below 50 mL/min.

For timed urine collection method see Creatinine Clearance — Measured. For IDMS-calibrated creatinine see the Revised Schwartz Estimate.

References

  1. Schwartz GJ, Gauthier B. A simple estimate of glomerular filtration rate in adolescent boys. J Pediatr. 1985;106(3):522–526.
  2. Schwartz GJ, Feld LG, Langford DJ. A simple estimate of glomerular filtration rate in full-term infants during the first year of life. J Pediatr. 1984;104(6):849–854.
  3. National Kidney Disease Education Program. GFR reporting recommendations. National Institutes of Health; 2010.