Glomerular Filtration Rate (GFR) Calculators

Use these GFR calculators to estimate kidney function for adults and children.

At this time, all laboratories should be using creatinine methods calibrated to be isotope dilution mass spectrometry (IDMS) traceable. In the US and other countries, nearly all methods from the major global manufacturers now have calibration traceable to an IDMS reference measurement procedure.1 Consequently, the calculators for older non-standardized creatinine methods are no longer available on this web site. Learn more about creatinine standardization.

GFR Calculators for Adults (for patients 18 and older)

In adults, recommended equations for estimating glomerular filtration rate (GFR) from serum creatinine include the Modification of Diet in Renal Disease (MDRD) Study equation (IDMS-traceable version) and the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation.

GFR Calculators for Children

Currently the best equation for estimating glomerular filtration rate (GFR) from serum creatinine in children is the Bedside Schwartz equation for use with creatinine methods with calibration traceable to IDMS2, 3. Using the original Schwartz equation with a creatinine value from a method with calibration traceable to IDMS will overestimate GFR. Read additional laboratory guidelines on calculating estimated GFR for children.

Schwartz Bedside GFR Calculator for Children IDMS-traceable
For use primarily in the U.S.
For use outside of the U.S.