eGFR Calculator CKD-EPI 2021

The CKD-EPI (Chronic Kidney Disease Epidemiology Collaboration) equation is a mathematical formula used to estimate the Glomerular Filtration Rate (GFR), which is the primary indicator of kidney function. GFR represents the volume of blood filtered by the glomeruli of the kidneys per unit of time, typically expressed in milliliters per minute per 1.73 m² of body surface area (mL/min/1.73 m²). The estimated GFR (eGFR) calculated by CKD-EPI is the currently preferred method for assessing kidney function in daily clinical practice, superseding older formulas like the Cockcroft-Gault and MDRD (Modification of Diet in Renal Disease) equations. The CKD-EPI formula was developed in 2009 (and subsequently revised, notably in 2012 and 2021) to be more accurate than the MDRD equation, especially at higher GFRs (i.e., kidney function closer to normal). The original CKD-EPI calculation uses four main variables: serum creatinine, age, sex, and race (specifically, a coefficient for Black Americans). However, the use of the race coefficient has become highly controversial and is being widely discontinued or replaced by new versions of the equation (like the CKD-EPI 2021) that omit race, or by equations based on other biomarkers like cystatin C. The eGFR calculated by this equation is fundamental for the diagnosis, staging (classification of severity from 1 to 5), and management of chronic kidney disease (CKD), as well as for adjusting dosages of medications that are excreted by the kidneys.