Renal function
CKiD U25 eGFR Calculator
Estimates glomerular filtration rate in children, adolescents, and young adults aged 1–25 years using serum creatinine, cystatin C, or both.
How the calculation works
- Creatinine: eGFR = κ × height (m) ÷ SCr (mg/dL).
- Cystatin C: eGFR = κ ÷ cystatin C (mg/L).
- Combined: arithmetic mean of the two estimates.
eGFR = κ × height ÷ serum creatinine
Important use notes
- Designed for patients aged 1–25 years with mild-to-moderate CKD.
- The combined estimate is preferred when both markers are available.
- Trends are often more useful than one isolated eGFR value.
- An eGFR category alone does not establish a CKD diagnosis.
Method and references
Primary equation: Pierce CB, Muñoz A, Ng DK, et al. 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.
Equation source: NIDDK eGFR equations for children, adolescents, and young adults.
This calculator is an educational clinical support tool and does not replace professional judgment or local guidance.
