Pediatric GFR Calculator

Written by Great Medico

Updated September 24, 2026 •2 min read

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Small differences in pediatric inputs can change the answer quickly. Pediatric GFR Calculator keeps the calculation focused on the age, weight, measurements, or clinical branch actually implemented in the plugin.

What this calculator does

Pediatric GFR Calculator uses Sex, Height, Serum Creatinine, Serum Cystatin C, and BUN to calculate pediatric eGFR estimates. Where supported, it also shows Cystatin C equation and Combined CKiD equation so the primary result is easier to check. It follows the exact field flow and engine behavior in this plugin rather than describing a different calculator with the same name. Children are not simply small adults: age, weight, gestational history, formulation, and clinical setting can change how a result should be used. Pediatric outputs deserve extra attention to units and the population for which the method was developed.

How to use it

Enter or select Sex, Height, Serum Creatinine, Serum Cystatin C, and BUN. Use the units offered by the calculator and keep paired laboratory or treatment values from the same clinical episode whenever the formula assumes that. If an entry is unknown, do not substitute a guess simply to obtain a number.

How the calculation works

The primary output is bedside Schwartz eGFR = 41.3 × height(m) ÷ serum creatinine. The tool also calculates a cystatin-C equation and a combined CKiD equation using height, creatinine, cystatin C, BUN, and sex.

Example

Using the sample values prefilled in this calculator, the primary result is 82.6 mL/min/1.73m² (Bedside Schwartz eGFR), Cystatin C equation is 70.7, and Combined CKiD equation is 77.2. This example demonstrates the plugin’s own calculation path; replace the sample inputs with verified values before interpreting a real result.

How to interpret the result

The three estimates may differ because they use different biomarkers and equations. Trends and the equation appropriate to the clinical/laboratory setting matter more than false precision in one number.

Limitations and notes

Creatinine- and cystatin-based pediatric eGFR equations are estimates and can be inaccurate with rapidly changing kidney function, unusual muscle mass, steroids/inflammation, or values outside their validated population. Use the equation appropriate to the lab and child.