eGFR Calculators for Adults & Pediatrics

Regardless of the equation used to calculate estimated glomerular filtration rate (eGFR), the eGFR value is an estimate and is not a precise measure of kidney function. Most estimating equations become less accurate as GFR increases. eGFR calculators that provide estimates without use of a race coefficient are preferred for adults and children.¹ Trends in eGFR are often more informative than a single point estimate, as trends allow for the assessment of kidney function change over time.

Adult eGFR Calculator

NIDDK’s eGFR calculator for adults uses the race-free Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equations to estimate GFR. The calculator may be used for people ages 18 and older.

For patients ages 18 to 25, we recommend using both the adult calculator and the pediatric Chronic Kidney Disease in Children under (age) 25 (CKiD U25) equation calculator. Comparing the estimates from both calculators may provide a more informed assessment of kidney function for the patient.

This calculator is for patients 18 and older. For patients ages 18-25, reference both this and the pediatric calculator.
Inputting both creatinine and cystatin C values provides a more accurate estimate.
Creatinine can be measured with serum or plasma.
These estimating equations become less accurate as GFR increases.
Learn about the equations used in this calculator.

Pediatric eGFR Calculators

The CKiD U25 calculator is the preferred calculator for use in children, as it exhibits less bias across a broader age range than the 2009 CKiD “bedside” calculator.² The 2009 CKiD “bedside” calculator is older, but the equation is still commonly used in routine clinical practice.³

To estimate time to end-stage renal disease (ESRD) in children, use the Estimating Time to ESRD in Children with CKD calculator, developed using data from the NIDDK-funded CKiD study and the ESCAPE study.⁴

CKiD U25 calculator

The CKiD U25 calculator may be used to estimate eGFR for children, adolescents, and young adults ages 1 to 25.

For patients ages 18 to 25, we recommend using both the pediatric CKiD U25 calculator and the adult calculator. Comparing the estimates from both calculators may provide a more informed assessment of kidney function for the patient.

This calculator is for patients 1 to 25 years old. For patients ages 18-25, reference both this and the adult calculator.
Inputting both creatinine and cystatin C values provides a more accurate estimate.
Creatinine can be measured with serum or plasma.
These estimating equations become less accurate as GFR increases.
Learn about the equations used in this calculator.

2009 CKiD “bedside” calculator

The CKiD “bedside” equation calculator uses serum creatinine and height to estimate GFR in children ages 1 to 16. The calculator is offered in conventional and SI units.

This calculator should only be used for children ages 1 to 16.
All estimating equations estimate GFR. A person’s actual GFR may be higher or lower than the estimate. GFR may be best assessed by monitoring trends over time rather than a single point estimate. Estimating equations become less accurate as GFR increases.
Learn about the equation used in this calculator.

References

[1] Delgado C, Baweja M, Crews DC, et al. A unifying approach for GFR estimation: recommendations of the NKF-ASN Task Force on reassessing the inclusion of race in diagnosing kidney disease. American Journal of Kidney Disease. 2022;79(2):268–288.e1. doi:10.1053/j.ajkd.2021.08.003

[2] Pierce CB, Muñoz A, Ng DK, Warady BA, Furth SL, Schwartz GJ. Age- and sex-dependent clinical equations to estimate glomerular filtration rates in children and young adults with chronic kidney disease. Kidney International. 2021;99(4):948–956. doi:10.1016/j.kint.2020.10.047

[3] Schwartz GJ, Muñoz A, Schneider MF, et al. New equations to estimate GFR in children with CKD. Journal of the American Society of Nephrology. 2009;20(3):629–637. doi:10.1681/ASN.2008030287

[4] Furth SL, Pierce C, Hui WF, et al. Estimating time to ESRD in children with CKD. American Journal of Kidney Disease. 2018;71(6):783–792. doi:10.1053/j.ajkd.2017.12.011

Last Reviewed May 2024

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.