GFR Calculators

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

GFR Calculator for Adults (for patients 18 and older)

In adults the best equation for estimating glomerular filtration rate (GFR) from serum creatinine is the Modification of Diet in Renal Disease (MDRD) Study equation. The original MDRD Study equation GFR Calculator is for use with routine creatinine methods. The IDMS-traceable MDRD Study equation GFR Calculator is for use with those methods that have been recalibrated to be traceable to IDMS.

GFR Calculators for Children

Currently the best equation for estimating glomerular filtration rate (GFR) from serum creatinine in children is the Schwartz equation.

Note that estimated GFR calculated using the original Schwartz equation will be influenced by the change to creatinine assays that are IDMS traceable. In general, such methods will produce lower creatinine results, which, when used in the original equation, will overestimate GFR. Thus, the eGFR may not accurately reflect the patient's kidney function.

Caution: It is very important to know the method used to measure creatinine in a blood, serum, or plasma sample, as it will affect the formula for estimating GFR in children. Read more to determine which calculator you should use.

PDA Version for Adults and Children

This PDA version includes adult (Original and IDMS-traceable) and children's calculators in conventional units for download on Palm and Windows Operating Systems.

Note to Children’s Calculator Users
This PDA download was developed in 2006 with the original Schwartz equation, using a k of 0.65 for adolescent males instead of 0.70. Also, the PDA download does not contain the IDMS-traceable Schwartz equation calculator, which was created in October 2008.

Additional Resources

• Frequently Asked Questions About Estimated GFR Values