Pediatric kidney function tool
Pediatric eGFR Calculator Using the Bedside Schwartz Formula
Estimate indexed GFR from a child's height and standardized serum creatinine using the 2009 CKiD bedside equation.
Online eGFR Calculator from Creatinine, Age & Sex (CKD-EPI 2021)
Enter serum creatinine, age, and sex to calculate eGFR online and estimate your kidney function using the current CKD-EPI 2021 equation.
Enter Your Values
Enter serum creatinine and height to calculate pediatric GFR using the Bedside Schwartz equation.
How this tool works
The calculator uses eGFR = 0.413 × height in centimeters ÷ serum creatinine in mg/dL. If creatinine is entered in µmol/L, the calculator converts it to mg/dL before applying the formula. The result is normalized to 1.73 m² body surface area.
The equation was developed primarily in children ages 8-15 with mild-to-moderate CKD using standardized creatinine assays. NIDDK now also describes CKiD U25 equations for children, adolescents, and young adults; the best equation depends on age, available biomarkers, laboratory reporting, and clinical purpose.
How to use it
- Use the child's current measured height and a serum creatinine result from the same clinical period.
- Select the creatinine unit exactly as printed on the report, enter both values, and calculate.
- Compare the estimate with the laboratory's pediatric eGFR, prior measurements, growth, urine results, and the treating clinician's assessment.
How to interpret the result
A pediatric eGFR is an estimate, not a direct measurement. The meaning of a result varies with age, growth, diagnosis, and whether kidney function is stable. Adult CKD-EPI equations are not intended for children.
A change may reflect a real kidney-function change, acute illness, hydration, medicine exposure, growth, muscle mass, or assay differences. Unexpected values should be confirmed and interpreted by the child's healthcare team.
Limitations and safety
- The bedside equation is less accurate at higher GFR and was not developed as a general screening equation for every healthy child.
- Extra caution is needed for infants, rapidly changing kidney function, unusual body composition, amputations, neuromuscular disease, or non-standardized creatinine assays.
- Do not use this educational result alone to diagnose CKD, change medicine doses, or decide on imaging, admission, dialysis, or referral.
Sources and method
Formula and interpretation checked against the following primary or authoritative sources. Editorial review date: September 9, 2026.