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. Most estimating equations become less accurate as GFR increases.

Using urine albumin and the urine albumin-to-creatinine ratio in individuals with or at risk for kidney disease is also recommended for a more complete assessment of kidney disease.

eGFR Calculators

While no single eGFR equation offers an overwhelming advantage in estimating kidney function for all patients or clinical situations, NIDDK supports the National Kidney Foundation (NKF)–American Society of Nephrology (ASN) Task Force's recommendation to calculate eGFR using estimating equations that do not include a race coefficient.

NIDDK also supports the NKF-ASN Task Force’s recommendation to use both serum creatinine and cystatin C to estimate GFR. The combined serum creatinine-cystatin C equation yields higher accuracy and less bias than equations using serum creatinine alone. Using the combined creatinine-cystatin C equation is particularly important when the eGFR is close to a critical decision value, such as in certain cases of drug dosing or kidney transplant evaluation. Using the combined creatinine-cystatin C equation may also be particularly important when assessing racial disparities in risk of kidney failure or death. Use of the 2021 CKD-EPI eGFRcr equation appears to attenuate these disparities compared to the 2021 CKD-EPI eGFRcr-cys, the 2012 CKD-EPI eGFRcys, and the 2009 race-based CKD-EPI eGFR equations.¹ These 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 Calculator

NIDDK’s adult eGFR calculator uses the race-free Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equations to calculate eGFR. The calculator may be used for people ages 18 and older. For details about the equations used in the eGFR calculators, and considerations for use, visit equations for adult eGFR.

Pediatric eGFR Calculators

NIDDK’s pediatric eGFR calculators use the Chronic Kidney Disease in Children (CKiD) equations to calculate eGFR. The preferred CKiD under (age) 25 (CKiD U25) equation 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. For details about the equations used in the eGFR calculators, and considerations for use, visit equations for children, adolescents, and young adults eGFR.

Previous eGFR Calculator for Reference

Estimating equations that include a race coefficient are no longer recommended. However, because the race-free equations may yield slightly different eGFR values compared to older equations, trends in eGFR should be assessed using results from a single equation. Therefore, NIDDK is maintaining the race-based calculator to enable comparison between results from the older and newer equations. During the transition to the race-free equations, understanding how results from the older race-based equations compare to results using the race-free equations will allow patients and clinicians to better understand changes in eGFR over time, independent of changes caused by a transition in estimating equations.

The previous eGFR calculator for reference uses the 2009 CKD-EPI creatinine equation with race coefficient to calculate eGFR in individuals ages 18 and older. For details about the equation used in the previous eGFR calculator, and considerations for use, visit previous eGFR equations.

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