What age range is the Bedside Schwartz formula validated for?

The 2009 Bedside Schwartz formula is validated for children aged 1 to 16 years. It should not be used in neonates or adults. A separate modified Schwartz formula exists for adolescents aged 13–18.

Why is the constant 0.413 used?

The constant 0.413 was derived from the CKD in Children (CKiD) cohort study using IDMS-traceable creatinine measurements. The original 1976 Schwartz formula used 0.55 (males) and 0.57 (females), but those values overestimated GFR with modern enzymatic creatinine assays.

What units does this calculator use?

Height is entered in centimeters (cm) or inches — the calculator converts inches to cm automatically. Serum creatinine must be in mg/dL. The result is expressed in mL/min/1.73 m², the standard unit for GFR in clinical practice.

How is CKD staging applied to the result?

KDIGO 2012 staging: G1 ≥90 (normal or high), G2 60–89 (mildly decreased), G3a 45–59 (mild-to-moderate), G3b 30–44 (moderate-to-severe), G4 15–29 (severely decreased), G5 <15 (kidney failure). Staging requires persistent abnormality over ≥3 months plus other markers of kidney damage for a formal CKD diagnosis.

Does this tool replace a formal nephrology evaluation?

No. This tool is for educational and informational purposes only. The Bedside Schwartz formula provides an estimate, not a measured GFR. All clinical decisions must be made by a qualified healthcare professional based on the full clinical context.

Pediatric GFR Calculator (Bedside Schwartz)

Name: Pediatric GFR Calculator (Bedside Schwartz)
Availability: InStock
Author: Nham Vu

Enter height and serum creatinine to calculate estimated GFR in children using the validated Bedside Schwartz formula.

Patient Measurements

Enter height and serum creatinine to calculate eGFR.

Height

Valid range: 1–16 years of age. Typically 50–200 cm.

Serum Creatinine (mg/dL)

Must use IDMS-traceable (enzymatic) creatinine assay.

Bedside Schwartz Formula

eGFR = 0.413 × Height (cm) / SCr (mg/dL)

Schwartz GJ et al. JASN 2009;20(3):629–637. Validated for ages 1–16.

Enter height and creatinine, then click Calculate.

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mL/min/1.73 m²

Estimated GFR

eGFR Range

0 30 60 90 120+

Calculation

eGFR = 0.413 × — cm / — mg/dL

eGFR = — mL/min/1.73 m²

KDIGO CKD Staging Reference

Stage	eGFR (mL/min/1.73 m²)	Description
G1	≥90	Normal or high
G2	60–89	Mildly decreased
G3a	45–59	Mild-to-moderate decrease
G3b	30–44	Moderate-to-severe decrease
G4	15–29	Severely decreased
G5	<15	Kidney failure

Clinical Note

For educational use only. eGFR is an estimate, not a measured value. All clinical decisions must be made by a qualified healthcare professional based on the full patient context.

Summary

Enter height and serum creatinine to calculate estimated GFR in children using the validated Bedside Schwartz formula.

How it works

Enter the child's height in centimeters (or switch to inches for automatic conversion).
Enter the serum creatinine value in mg/dL from a standard laboratory report.
The calculator applies the Bedside Schwartz equation: eGFR = 0.413 × height(cm) ÷ SCr(mg/dL).
The result in mL/min/1.73 m² is mapped to the KDIGO CKD staging system (G1–G5).
Review the interpretation and clinical note to guide next steps.

Use cases

Bedside estimation of kidney function during pediatric nephrology rounds.
Screening for chronic kidney disease in children with diabetes, hypertension, or structural renal anomalies.
Dosage adjustment calculations for renally-cleared medications in pediatric patients.
Monitoring kidney function over time in children on nephrotoxic therapies.
Medical education and training on pediatric renal physiology.
Pre-operative renal function assessment in pediatric surgical patients.

Frequently Asked Questions

Last updated: 2026-07-24 · Reviewed by Nham Vu