Estimated Glomerular Filtration Rate Calculators
Estimated glomerular filtration rate (eGFR) calculators provide an estimate of kidney function. eGFR serves as a key marker for chronic kidney disease and is calculated using estimating equations that may not always be precise. Estimates of GFR may be higher or lower than a person’s actual GFR, and uncertainty increases as GFR increases.
Measures of protein in the urine, such as albumin, can also be used as an indicator of kidney disease, independent of eGFR.
While no single eGFR equation offers an overwhelming advantage in estimating kidney function for all patients or clinical situations, the NIDDK supports the American Society of Nephrology (ASN)–National Kidney Foundation (NKF) Task Force's recommendation to calculate eGFR using estimating equations that do not include a race coefficient.
The NIDDK also supports the ASN-NKF Task Force’s recommendation to use both serum creatinine and cystatin C to estimate GFR in adults, when cystatin C is available. The combined serum creatinine-cystatin C equation yields slightly higher accuracy and less bias than equations using serum creatinine alone. Using the combined serum creatinine-cystatin C equation is particularly important when the eGFR value is close to a critical decision point, such as when determining drug dosing or kidney transplant eligibility. The recommended equations were derived primarily from racially diverse populations from the United States and Europe, and may have variable accuracy in different global populations, particularly when using serum creatinine alone.
Adult eGFR Calculators
NIDDK’s eGFR calculators for adults use the 2021 race-free Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equations to calculate eGFR. These calculators may be used for people ages 18 and older.
Pediatric eGFR Calculators
NIDDK’s eGFR calculators for children and young adults use the Chronic Kidney Disease in Children (CKiD) equations to calculate eGFR. The preferred CKiD U25 calculator may be used for children and young adults ages 1 to 25. The 2009 CKiD “bedside” equation calculator may be used in children ages 1 to 16.
Estimating equations that include a race coefficient are no longer recommended. However, to best understand change in a person’s kidney function over time, all the eGFR values must be calculated using the same equation. If different equations are used, some of the change in eGFR could be a result of using a mix of race-based and race-free equations as opposed to a change in actual kidney function. Therefore, NIDDK is maintaining the race-based calculator to enable comparison between results from the older and newer equations. This will allow patients and clinicians to better understand changes in eGFR over time, independent of changes caused by a transition in estimating equations.
The historical eGFR calculator uses the 2009 CKD-EPI creatinine equation with race coefficient to calculate eGFR in individuals ages 18 and older.
This content is provided as a service of the National Institute of Diabetes and Digestive and Kidney Diseases
(NIDDK), part of the National Institutes of Health. NIDDK translates and disseminates research findings to increase knowledge and understanding about health and disease among patients, health professionals, and the public. Content produced by NIDDK is carefully reviewed by NIDDK scientists and other experts.