eGFR (MDRD) Calculator

About this calculator

The 4-variable MDRD equation estimates glomerular filtration rate (eGFR) — the standard measure of how well the kidneys filter blood — from serum creatinine, age, sex, and race, without requiring a urine collection. It was derived from data collected in the Modification of Diet in Renal Disease (MDRD) study, a National Institutes of Health-funded trial published by Levey and colleagues in the late 1990s and refined in 2006 to work with standardized (IDMS-traceable) creatinine assays used by modern labs.

Nephrologists and primary care physicians use MDRD-derived eGFR to stage chronic kidney disease (CKD) into categories from G1 through G5, decide when to refer a patient to a nephrologist, and adjust dosing for kidney-cleared medications. It has largely been supplemented or replaced in many labs by the CKD-EPI equation, which is more accurate at higher, near-normal GFR values, but MDRD remains widely reported and referenced, especially for patients already diagnosed with reduced kidney function.

Enter a creatinine value along with age, sex, and race to see the estimated GFR this equation produces, expressed in mL/min/1.73m².