- Enter the child's standing height (centimetres; an optional inch toggle is provided).
- Enter the serum creatinine — choose mg/dL or µmol/L (µmol/L is converted internally as mg/dL = µmol/L ÷ 88.4).
- The estimated GFR (mL/min/1.73 m²) and a reference CKD-stage descriptor update automatically.
- Use only when the serum creatinine is IDMS-traceable / enzymatic and the patient is a child or adolescent (≈ 1–18 years).
All computation runs in your browser; no values are stored or transmitted.
When to Use
Use the Revised Schwartz Equation to estimate GFR in children and adolescents (roughly 1–18 years) from standing height and a standardized serum creatinine. It was derived in the CKiD (Chronic Kidney Disease in Children) cohort and is validated for the routine assessment and monitoring of pediatric kidney function — staging CKD, tracking trajectory over time, and informing renally cleared drug dosing.
Appropriate population
Children and adolescents (~1–18 years) with measured standing height and an IDMS-standardized enzymatic serum creatinine. Especially useful in pediatric CKD clinics for staging and serial monitoring of GFR.
When NOT to rely on it
Do not use in adults — use Cockcroft–Gault or a CKD-EPI estimate instead. The 0.413 constant assumes an IDMS-traceable enzymatic creatinine; a non-standardized (Jaffe) assay invalidates the estimate. Accuracy falls at extremes of muscle mass (severe malnutrition, amputation, neuromuscular disease, marked obesity), in acutely changing (non-steady-state) creatinine, and in very young infants. For research-grade precision, a cystatin C-based or combined Schwartz estimate may be preferred.
Pearls & Pitfalls
This is the BEDSIDE revised Schwartz
The single-constant bedside formula — eGFR = 0.413 × height (cm) ÷ SCr (mg/dL) — replaced the older age/sex-specific 1976 Schwartz constants (0.45 infants, 0.55 children, 0.7 adolescent males), which overestimated GFR once creatinine assays were standardized to IDMS. Enter height in centimetres; the constant 0.413 is fixed for all ages in this bedside version.
The 0.413 constant is assay-specific
0.413 was calibrated to IDMS-traceable enzymatic creatinine. If your laboratory still reports an uncalibrated Jaffe creatinine, the result will be biased — confirm the assay before trusting the number. The equation assumes steady-state kidney function; it is not valid during rapidly rising or falling creatinine (AKI).
Pitfalls
(1) Height must be an accurate standing (or recumbent length in the youngest) measurement; estimation errors propagate directly. (2) Muscle mass drives creatinine — cachexia or muscle-wasting disorders falsely elevate eGFR, while high muscle mass lowers it. (3) The adult KDIGO G1–G5 categories shown here are a familiarity reference only; pediatric GFR is age-dependent and a value that is "normal for an adult" may be low for a healthy child. (4) Do not apply during AKI or to adults.
Why Use It
Measured GFR (e.g., iohexol or inulin clearance) is the gold standard but is impractical for routine pediatric care. The Revised Schwartz Equation gives a reliable, instantly calculable estimate of GFR from only height and a standardized creatinine — values already available at every clinic visit. Because it was re-derived against IDMS-standardized creatinine in the CKiD cohort, it corrected the systematic overestimation of the original 1976 formula and became the de-facto bedside standard for diagnosing, staging, and longitudinally monitoring chronic kidney disease in children, as well as for adjusting renally cleared medications. Its simplicity makes it ideal for the bedside, the ward round, and resource-limited settings.
Revised Schwartz Equation — Bedside Pediatric eGFR
Enter the child's standing height and serum creatinine. The estimated GFR and a reference CKD-stage descriptor update automatically.
⚕ Schwartz GJ, Muñoz A, Schneider MF, et al. J Am Soc Nephrol. 2009;20(3):629–637. The G1–G5 descriptor uses adult KDIGO 2012 thresholds and is shown for reference only; normal GFR in children is age-dependent. Valid only for an IDMS-traceable creatinine in steady state; not for adults or during AKI. For licensed clinicians — does not replace individualized assessment.
Next Steps
Interpret the estimated GFR in the context of the child's age and clinical trajectory, not against a single adult cut-off.
- Confirm the result is based on an IDMS-standardized enzymatic creatinine and an accurate height before acting on it.
- For a reduced or declining eGFR: stage with KDIGO pediatric criteria, quantify proteinuria (urine protein/creatinine ratio), measure blood pressure, and trend GFR over serial visits to define trajectory.
- Adjust the dosing of renally cleared medications to the estimated GFR, and avoid nephrotoxins where possible.
- Refer to or co-manage with pediatric nephrology for persistent eGFR < 60, significant proteinuria, or progressive decline.
- Where precision matters (e.g., transplant work-up, chemotherapy dosing), consider a cystatin C-based or measured GFR.
Evidence & References
Formula (Bedside Revised Schwartz, 2009)
| Parameter | Definition | Notes |
|---|---|---|
| eGFR | 0.413 × height (cm) ÷ SCr (mg/dL) | Result in mL/min/1.73 m² |
| 0.413 | Bedside constant (k) | Calibrated to IDMS-traceable enzymatic creatinine |
| Height | Standing height in centimetres | Recumbent length in the youngest infants |
| SCr | Serum creatinine in mg/dL | µmol/L ÷ 88.4 = mg/dL |
Worked example: a child 100 cm tall with a serum creatinine of 0.5 mg/dL → eGFR = 0.413 × 100 ÷ 0.5 = 82.6 mL/min/1.73 m².
CKD-Stage Reference Descriptor (adult KDIGO 2012)
| Stage | eGFR (mL/min/1.73m²) | Description |
|---|---|---|
| G1 | ≥ 90 | Normal or high |
| G2 | 60 – 89 | Mildly decreased |
| G3a | 45 – 59 | Mildly to moderately decreased |
| G3b | 30 – 44 | Moderately to severely decreased |
| G4 | 15 – 29 | Severely decreased |
| G5 | < 15 | Kidney failure |
These adult KDIGO categories are displayed for reference and familiarity only. Normal GFR rises through infancy and childhood, so a value that is "normal for an adult" may be low for a healthy child of a given age. Stage pediatric CKD using age-appropriate KDIGO pediatric criteria.
References
- Schwartz GJ, Muñoz A, Schneider MF, et al. New equations to estimate GFR in children with CKD. J Am Soc Nephrol. 2009;20(3):629–637. doi:10.1681/ASN.2008030287.
- Kidney Disease: Improving Global Outcomes (KDIGO) CKD Work Group. KDIGO 2012 Clinical Practice Guideline for the Evaluation and Management of Chronic Kidney Disease. Kidney Int Suppl. 2013;3(1):1–150.
